My first feedback that I want to mention (which I don't see anybody else talking about) is 'why can't you place starbases?'  

I don't want to have to micro manage my little ship to fly him over to a spot where I want my base.  I want to click on him, tell him where I want the star base, then go work on other things expecting him to fly his own butt to where I want the base and build it.  It should be the same as any other building.

This isn't a problem for the mobile starbase, because it will move around on its own after being built (which I have other feedback on).    I don't think a massive starbase like that one should also use the same pathing function as regular ships.  I know this is just being nit-picky (you asked for feedback) but I don't like having to watch my starbase be forced to cover half the gravity well in an over-sized U-turn just to turn around.  I mean a giant death star should be able to just turn in place.  That seems like it would actually use less fuel to rotate something of that mass.   On regular ships you'd want them to keep moving as to not be hit by incoming fire, but nobody is going to miss a starbase!  Its the barn wall of space.   So I think the starbase should just rotate in place, then move in mostly straight lines.   Especially because that base looks like its got an engine on both sides.

Another 'why can't you' is why can't the advent starbase build mines?  I mean, I understand the fact that regular capital ships shouldn't build mines... that would be just broken, but if hangers can build them I would think my starbase with fully upgraded hangers built into could?   I can store like 12 squads inside, couldn't just a few of them be remote mines?  Even if its not available untill you have 3 hanger upgrades, it should be available sometime.   It would make the advent starbase even more of a wall too (which I feel it has very limited range.  Which is ok, provided that within its range = death zone)