if you put like 10.000 credits on a mission for the Ai to destroy some ships of another Ai or player and the Ai refuses to do so (wich it does quite all the time) all of the money is lost... u don't even get it back or the Ai gets it.. it just vanishes
is this intended ? cuz it kinda sux:D there should be a time of no possible negotiation after you propose a mission like that and dont loose all of the money
so far diplomacy is merely a setback .. u can do the same things like in vanilla with the difference you have to spend money first and U give missions wich the Ai never accepts 
i hope there are huge changes coming cuz right now its kinda pointless
the improved Ai (lol dumber as before) and the harder pirates dont make up for the promised diplomatic boost wich isnt there..
1 ship is all u get and the research to lower enemy planets allegiance is at the same lvl with the "now we can destroy the lame diplomats" booyahh hmm 
still very alpha..
im sorry if i was a little harsh but i love this game and there where great expectations for the diplomacy addon
what about if you could push your culuture with diplomacy a bit further
like people on other planets like yours more and rebell and switch completly
or a favorite of mine on maps with inhabited neutrals an option of the envoy cruiser to manipulate the neutrals to join your empire (maybe also working with culture)
an complete overhaul of the neutrals would be much appreciated anyway
just make em like a normal Ai who just don't leave their gravity well..