Sorry, I can't read all 317 posts, so if I repeat anything, my bad...
From a Modders Stand Point, I'd like these features:
1. If a technology follows an "Impossible" tech and you are playing as a race who doesn't have that tech, any technology following that branch should be hidden from few - it would cut down on some clutter
2. Ability to add in multiple starbase models for each race - I've asked if this was possible and have yet to seen it done, or to get a response, so I'm thinking it isn't capable now. But having the ability to make it so each race has its own style of starbases would be an awesome feature, developers wouldn't even need to add in more styles, let us modders do that

3. Give a "hide" tech command. Seems almost pointless, but you can do a lot with it actually.
4. Ability to MOD in a way to move a starbase - normal game keep it how it is, but make it so you can mod in say Propulsion modules for starbases - This would satisfy a lot of fans out there, and still let you keep the original game balanced.
5. I'm just being hopeful on this one - but ability to mod in a starbase module that acts as the super event to destroy a planet - again not in to the real game, but make it a moddable possibility.
Okay, I'm going back to modding now, but I'll be back with some more