One of the most annoying things to me about GalCiv and many 4X is tech trading.
I saw this old post about it https://forums.galciv3.com/449087/page/1/#3407634 but couldn't reply to it, but it sums it up nicely by stating it's one of the most exploitable mechanics in 4X, and that's so true.
You can watch people playing older versions of Civ on high difficulties and a large part of success is manipulating bad AI to do tech trades to keep up. That's not really strategy, that's cheese. 4X need less or no cheese, not built in cheese.
In GC3 the AIs basically do collective research, because between the AIs and the minors, they end up trading a ton and it's like you against everybody as far as researching goes (or you do some trading too, which is not my idea of fun). I play with rare minors, which still seems to yield a huge amount of minors, and they're basically conduits for the AIs to get all techs with ease.
Or, as a player, you leverage moronic AI and trade techs to gain an advantage yourself.
Either way, either the AIs exploit you, or you exploit them. It's not a good game mechanic even if exploit is one of the 4 X's.
In some games the no tech brokering thing can help but not really in GC3, because there are so many minors that you still end up with collective research.
If you turn of tech trading entirely it seems to cripple the AIs because they just don't seem to prioritize researching enough or to know that they need to due to lack of trading being available.
So IMO, get rid of tech trading entirely and either go the Civ 5 route and have something like research agreements, or something like that. We already have tech treaties in GC3. Something like this is good because it means you need to have good relations with factions to boost your tech - or need to be dominant and be able to demand tech streams via coercion.
Something, anything, would be better than having situations like the current GC or like Civ IV where the AIs do collective research.