Knowing the voting power is directly represented bz number of population...there should be other aspects similar. Otherwise only explosive expansion secures diplomatic victory.

As it stands right now explosive expansion is the only thing that ensures victory, period! I hope this will change, because right now it is not fun at all. But then again there is a warning that the game might not be fun while still in Beta. 

I do however agree, that the constant UP resolutions are annoying rather than helpfull, so I support having more metrics play a role in number of votes, say your tech level or your military power etc.

If all else fails you can reduce the number of UP-meetings in the game setup screen.

In addition to changing the game setting for how often the UP should meet, as Rhonin said, (sorry can't quote right now), perhaps there should be a UP Resolution for meeting frequency that modifies the in-game setting? So one could, for example, halve the frequency?

even setting the game option to rare they meet way to often for the selection of proposals.  The popups would be cooler if one civ was asking for something, like asking the UP to order the civ attacking them to cease.  The chair could then be presented with several options to choose from for the UP to vote on.

Well, I also found, that if you vote for anything (like immediate peace aso.) does not work. All before ordered AI ships will fullfill their orders and so you'd be still at war or they are settling into your ZOC even if you signed the treaty 1 turn before. I guess the UP decissions are yet not bound to the alien ship orders.

@ForesterSOF: Where you think you could alter setup so AI is doing like UP has voted?

@ForesterSOF: I do know this, but you can't force AI to follow the choices of the UP. You only choose the frequency of the UP...even to cut UP off, but I'm sorry, this is not the fitting answer. 

In any cases, I started a positive vote to force peace the AI 

1. ignored it
2. declared war the other turn

So far it seems there is no direct connection between UP, AI diplomatics and incoming fleets. (besides, my direct enemy vote for me to get chairman of the UP anyhow we are in war or not, which seems quite unbalanced)

It would be cool if one or more civs could call for a UP meeting to ask for something based on current game events.