lets try a few answers.

2) gauss canons, or defense structures in general, are only really useful when used in clusters and in combination with repair centres and maybe hangars. beware though that defenses in this game do not serve so much as a defense in itself, but rather a network to support ships stationed there. thus, with a clever ship and structure layout you can drive off a much larger force.

4) not at all. for one thing, distance to homeworld matters on the amount of resources generated. its handled by allegiance, which is the % of resources you get from full due to distance. next, for taxes ie credits, the level of planet development is important, higher levels generate more resources. and quite a lot I may add. then there is research which can either increase the population limit on certain planet types which then gives you more money or increase metal/ crystal rates. lastly, there is also logistics structures like trade ports (for credits) or refineries (for metal/ crystal) that have to be researched and can be placed throughout your little empire. there are also a few race specific ways to gain extra resources, but that's a bit too specific for now.

I'm not really getting the other questions. I think the speed bonus for multiple labs - if any - is pretty small. does not really matter though as long as you don't play on slow mode.

as for resources for tech vs military: that is really something that requires a bit of experience to decide. it is imo one of the central challenges of this game to balance the need to improve your empire and your military in various ways. I also would say that there is no real generic strategy to go for, you should try to adapt to your surroundings, that is the planets in your vicinity, the size of the map, the proximity of enemies, the race you are playing, etc. in larger, longer maps, you can risk going for cilivilan improvements ( a few at least) first, while in smaller ones, you are usually better off going straight for a few key military techs, like certain ship types and such.

so, don't despair, it will get easier and clearer as you play. if you have problems with pirates, you can try buying them off and get them to attack another player. alternatively, if you feel overwhelmed in the beginning, you can also turn them off if you want.

-you should probably spend your resources making defenses for your planets rather than spending to get labs, if you spend all your resources on teching up you wont have much of an army now would you?

-try to spend some money on developing your planets to get a better credit income rate,so in case pirates are ready to raid you can spend some credits on your enemies

-if you must tech up try to spend some money the research of trade ports and refineries, also the upgrades for extractors

-try to make 2 or more groups of units instead of 1 big group, a group of units might be able to scare away the attack of the enemies

-DON'T expand until you have a capable army otherwise the enemies might attack your troops and planets and you're stuck with a very weak army

-you only need 3-5 planets before you can start turtling, if you develop those planets you will have a good enough economy to support your fleet

-pirates arent really a threat unless the raid strength is high, other than that a capital ship should be able to handle weaker raids, if it is a big raid make some planet defenses(i usually use hangar defence) along with a small group of ships(they can distract the pirates while strikecraft take them out)

Note: pirates usually go for trade ships, colony ships and refinery ships, use this to your advantage: while they are busy attacking those ships you attack them, the REAL important thing is to have defences for your planets, do that and send the pirates home to their mommies

Also you just don't waste so much money to deter pirates, you could build ships with that money and destroy them when they come to you.