Firstly, GJ, fun game, the mechanics are interesting and I don't regret acquiring the game. The lack of an online gaming community is, however, absolutely disturbing. I typically play RTS type games over 4X, but the seemingly seamless convergence of the two styles in Sins is very attractive. The problem, I think, is scope and pace- the timeframe over which particular elements are and can be utilized within a game. The ultimate observation is this; it takes too long to enjoy the features of the game. Games take too long, yes, but it also takes too long to enjoy the features and strategic diversity. Here are some of my thoughts as a veteran of several successful competitive RTS games (that is, those that get played in WCG).

Combat System and Movement
Battles simply take too long. They'd be even more fun to watch if things occasionally died within a few seconds. I haven't tested it, but the time it takes for one Cobalt to kill another Cobalt feels longer than a minute, which is an incredibly long amount of time considering how quickly the unit is produced. If your tax rate is ~10, it only takes about 30 seconds to get the res to make the guy and another 15 seconds or so to build him. Most RTS games utilize a system where the total cost of a unit's production (in time) is much much greater than the time it would take for it to kill itself (if it could). IE. a Zergling takes X amount of time to gather the resources for and train and it takes Y amount of time for a zergling to kill another zergling. In every successful RTS game ever made, X is ALWAYS greater than Y. The issue here is pacing, how quickly battles begin, end, and respond to micromanagement. Increasing damage AND speed by the same proportion will NOT effect balance in any way. If I have 30 cobalts and my opponent has 20, there is no sensible reason why the winner of that battle needs 4 minutes to be decided. Equally, if my opponent were to recieve a reinforcement of 15 cobalts at the 2 minute mark of the 4 minute battle, it could've all just happend in 1 and 2 minutes respectively. All damages and movement rates of ALL units should be increased by a proportional amount. This does nothing to balance except speed the sluggish combat system up. This also makes raiding more viable as peons/extractors are slightly more vulnerable- which makes the game more interesting. It also can allow a player the opportunity to focus more on aggressive play without being too dependent on colonization (if your capital planets are far away, games are more of a rush to see who can gather more planets, and then fight)- this is just one time-limiting factor of strategy that could be sped up with increased movement rates. It would also be neat if ships moved more quickly through gravity wells that have no unfriendly units (that way it doesn't take an hour to move from planet to planet).

Tech Tree, Economy and Strategy
This is a huge gripe for me. Strategy games employ technologies so that strategic diversity may be employed. The Tech Tree in Sins isn't necessarily too slow, but it is much too linear and limited. An example explains this best- A Novalith cannon is pretty powerful and useful in a number of ways- if it was available without research at the beggining of the game, would that be a huge advantage? I don't think so. The cost is soooo freaking high that the risk of employing a strategy that focused on acquiring a tech-less novalith ASAP to win a game would be nigh impossible. The opportunity cost of a novalith is about 20 cobalts. A difference in military force of 20 cobalts between you and an opponent is GG. At the same token, if your opponent is 'booming/turtling' and focusing on colonization and defense, he should lose to a threatening "novalith rush". All the tech tree in Sins does is severly restrict strategy and the time it takes to take advantage of game features. I think that the prerequisites for technologies in Sins are simply too expensive to be remotely considered in the scope of a multi-player game. Another useful comparison can be made between a Javelin and Cobalt.

Lets consider this untested yet realistic scenario. My opponent knows that my primary focus will be on maximizing the number of cobalts I can to use in a quick early rush. My opponent decides that pursuing Javelins to counter my cobalts would be wise. So he buys and builds two Military Labs and then buys the Javelin upgrade. He makes Cobalts while waiting for the Javelin to become available, and then will switch to making only javelins. As a function of time, the cobalt spammer can afford to drop a second frigate factory and double spam cobalts until he reaches his logistic limit and then attack. Who wins? The cobalt spammer has almost no chance of losing this fight. The opportunity cost of two labs and the research is more cobalts than javelins would be able to handle when they become available.

This scenario isn't necessarily accurate, it's just an illustration of why a restrictive tech tree is bad (though NO restrictions can be just as bad, but that isn't the problem here). There is very little fluidity in strategy and decision making when techs are so incredibly expensive. The great thing about Sins is that the scale is huge, a game will go on as long as two players are skillful enough to compete- the bad thing is that the game HAS to go on for a long time. The scale of a game should be dependent upon player ability and decisions, it should not be a requirement. The linear and restrictive tech tree in Sins makes it very difficult for interesting strategies to develop in a short period of time.

If in that same example, the javelin tech-er takes a longer period of time between building M-labs he may be able to buffer enough Cobalts to get Javelins out in a reasonable amount of time, but this is just a waste of time. Strategies don't need to take that long to develop. There are also certain techs that are MUCH more valuable than others and are MUCH MUCH cheaper and available sooner.

Lets take the same example, but instead of double factory cobalt spam, the cobalt spammer drops an m-lab and gets 3 levels of military upgrades (2 armor + 1 hulling has the best synergy i think)- which again, is about the same opportunity cost as two labs and the javelin tech. Who wins? I would easily stake it on the cobalt-er, who is also in a better position to get javelins after he's already won the fight (and would then have stronger javelins). This, in essence, is just 'better' strategy, but it continues to illustrate the problem with tech tree.

Finally, lets look at one other example, this time on the map "Point Blank." PB always has 2 desert planets for capitals, 2 asteroids and 2 ice planets. Lets say I wanted to focus on being expansive and I try to quickly acquire an ice planet, hoping that the added resource benefit will allow me to stave off an aggressive player attacking my capital. Oh wait, I need two civic labs, and exploitation before I have to pay another 1000 credits or so to avoid underdevelopment? If we grabbed the 4 crystal ice planet that's another 1k before it's really doing anything. IN PB, getting the ice planet costs 4K + Underdevelopment tax rate! Lets take a 'real' map as an example. It is going to take a few planets in travel time before you can reach your opponent, that buffer-time can afford the cost and time to colonize. But- that's just more time! The pace of the game needs to be sped up, techs should, as a result, have greater impact. The best way to do that without radically changing the mechanics is to reduce the prerequisites and make colonization pay off sooner.

Finally, lets look at the logistics upgrades (fleet). They increase your cap by placing an upkeep cost on top of your income rates. The more planets you acquire the larger the fleet you need, the more logistics you need, the greater your upkeep cost. This relationship makes other techs highly unaffordable because your income rates don't change that much- as soon as you could use a new technology you're at your cap, and won't really be able to afford a new tech. Say I'm capped on frigates and I'm losing a few regularly. If I had Javelins I wouldn't be losing as much- but look at the cost of the javelin upgrade/implemention when compared to just upgrading logistics. I've found it effective to stick with the cobalt until I'm at a higher logistics level, at which point the cost of my second M-Lab can be split between the Javelin upgrade and the Logistics upgrade, which makes the whole relationship more cost effective. This is fine and all, but it is restrictive because that's basically the BEST way to do it. Your income rates don't even change all that much until much later in the game. If you simply look at a graph at the end of a game, you may notice that your income rate is exponential; however, very early on in the game your income grows linearly. Developing your credit growth rate isn't as simple as training a new peon and putting him on gold- you need to either colonize and develop (which is expensive and timely) or get trade posts (which are expensive and timely)- all of which take a long time to pay for themselves. This time-cost makes it difficult to acces the tech tree when just spamming Cobalts, in one way or another, is so much cheaper. Also, the upkeep cost also makes producing ships at a higher rate more or less impossible. If I wanted to use two factories at the same time, relatively early in the game, the time it would take for two active factories to be affordable would not be sooner than it would be necessary to upgrade logistics. Considering the value of a logistic structure slot, it's basically impossible to put yourself into a position where you can make multiple units at a time until much later into the game.

In a competitive one on one game, If I'm not constantly making ships, I should die. There is never really a point where your economy gets strong enough to afford the techs necessary to colonize extensively, which is the only way to improve your economy to be able to afford more techs or more military. The result is a general lack of fluidity and slickness that allows games to take off and get interesting quickly. What makes strategy games attractive is the freedom and diversity of strategy. The tech tree in Sins has NO freedom and only has diversity after an hour+ of gameplay.

So we have a relationship between income rates, fleet upkeep costs, the cost/time of techs and the cost of development which doesn't make for the most fluid, timely and interesting games. This is a slightly more difficult problem to tackle in a simple manner. A few things I think that would help.

Increase the cost of planetary logistic slots.
Reduce the cost of planetary max pop-cap development (or alternatively, increase the effectiveness vs underdevelopment).
Greatly reduce the cost of Labs.
Increase the rate that labs modify the research rate.
Reduce the cost of domestic structures (media,refineries,trade), but increase their build time.

Techs that unlock access to ships and orbital structures should all have no prerequisite cost attributed to them (IE not require other techs or a number of labs), instead they should just have a high research time and initial cost (the current costs should be reduced, and some should be close to free). The more labs you have, the sooner a tech can be made available, but you're not limited by the number of labs you have (and by inheritance, the number of planets you have) in terms of options.

The military aspect is a quick a fix. Just multiply the speed/damage of all units by a K, and the game becomes that much more enjoyable and viable for online play. The domestic side is a bit more challenging, but the tech tree must be less dependent upon games lasting a long time, otherwise there are a ton of features that are entirely pointless in the scope and pace of a competitive 1v1 match.

That's all I can think of for now...