I 'd like to see the ability to limit tech trading with allies so you can help them without having that tech spread by the AI. I'd limit it like this:
You can set a traded good to not be tradeable by the AI via diplomacy (can still be stolen from them). You could only do this with races you are allied with or who ask you for help and only when you give the tech away free. This would provide a way to give real help to races you want to support without them trading it to all your competitors in the galaxy. Of course if the race in question is invaded your enemy may get the tech from them that way so you'd still have to be careful.
Also it might pay to limit it to 4 or 5 techs so the player can't stop the AI making diplomatic trades by giving them a bunch of tech.
