Ok I'll tale some time to comment since you need it so much
1. Trade Federation Droid Control Center: I suggest you boost this building's strength. People are really going to aim for these buildings in early games so boost their strength. To compensate, make them costlier to build then other CC.
2. Heavily Lower the ressource gathering buildings or grant another PK droid to compensate the ressource handicap with the droid control center.
3. What are the odds of a Battle Droid living long enough to be promoted
Anyway this seems a bit odd. Battle Droids aren't soldiers who can normally gain experience, it should be in their programming or something. I don't see how a droid can be promoted.
4. I don't think the Droideka needs nerfing but I had the idea that the droideka shield would be up only when it stands still. While it's moving its armor would protect it. Just an idea, I don't know if it's balanced or not.
5. Perhaps your Troop Carrier requires a smaller carry capacity. 20 is...a lot.
6. The MTT has only a carry capacity of 20 while the Troop Transport also has 20? I thought the MTT could carry a lot more.
7. Corpses for wealth
Nice idea. Metal would sound better though but wealth is ok.
Thats pretty much everything for now.
By the way, the only cannon that looked nice in SWGB is the Trade Federation's one