There's been talk about how 'feeding' in early game hurts game balance. For example, feeding a Vasari player to starbase the enemy might not be how the game was intended nor balanced for. I don't play online myself, but I can see the point in this.
Just I wish that, for example, you could research espionage to provide you on how much resources at hand a certain player has. Could be a little panel that goes "According to our (relatively weak, nonexistant, strong, overwhelming etc) espionage strength on Player X, we can determine that this faction has approximately X metal, X credits, and is losing X credits from upkeep. This player is currently researching X."
Something like that, obviously, I'd envision a "Espionage Fund" like function in the diplomacy panel that allows you to direct a certain amount of income towards espionage at that player, and likewise one could feed money into one's own counterespionage efforts.