Whew, such a long read lol. Well from reading the entire thread I had some ideas, but forgot most of them lol. However I did have an idea for the interdictor.
The canon interdictor cruisers created false gravity well signitures, that prevented ships from entering hyperspace (Do to hardcoded safety mechanisms in the hyperdrives). So the interdictor would project a fake gravity well infront of the fleeing ship, preventing it from escaping. The gravity well was extremely large, atleast several kilometers in diameter I beleive.
So what you could do in the game, is give the interdictors a toggleble ability so they can project gravity wells wherever they wish for a certain range. The downside to this though, is that when an interdictor projected a gravity well, it could barely move (Do to the odd gravitational forces presented on it, and also because it had to drain almost all it's power to the gravity wells.) Because of that drain in power, they also had minimal weapons and shields.
Also, for the SW map, I noticed all your referance maps were those cheap ones, so here's the most accurate map I have ever found.
[URL=http://imageshack.us]

[/URL]
And just an FYI, I'm a HUGE SW nerd lol. So I can give good information on ships and abilities and whatnot if you need.