I grabbed Beta 3 with hotfix (0.95) and played a game with each race in single player vs 6-8 AIs depending on map.  Impressive work IC, this is a very cool addition to a great game.

Bugs:

1.  AIs accepting pacts then instantly cancelling them.  After reaching higher levels of relationship they stop doing it but at the moment it's pretty much useless to offer a pact near the minimum relationship values.

2.  Rarely after an AI cancels a pact the effects are still there and getting the pact back again can double the bonus.  Vasari starbases with over 31,000 hp are impressive to say the least.  I only saw this for sure when playing Vasari with the HP pact which was easiest to notice.  It happened after a bunch of rapid and repeated pact offers and rejections so I'm guessing one cancel didn't actually cancel the effects.  I think it also happened with the trade pact when I was playing Advent as well but that's harder to notice than a huge hp bonus x2 on everything in your empire.

3.  Sometimes the pacts change the relationship level by a good amount.  With all three races the offering / acceptance / rejection of pacts instantly changed relationship levels by up to 3.00 occasionally.

4.  When playing the TEC the supply pact didn't work correctly.  The supply number went up but I couldn't actually use it.  I could see a little over 800 supply available but when I tried to build a few kodiaks I was told out of supply.  However when playing the Advent it worked exactly as advertised.  When playing Vasari I paired up with an Advent so didn't get to see that combo.

5.  The 'Truth and Reconcillation' tech in the Advents tech tree says 'string not found' for a description.

Balance (personal opinions):

1.  Vasari armament pact is overpowered, 20% fire rate to every single weapon on every single ship and structure is ungodly powerfull.  15% would be still be incredible and more than worth the effort.

2.  The TEC missile pact really should affect the psionic surge weapons on Advent starbases if there's anyway at all to make that work.  For sure some pacts are going to be better for some races than others but that's the only one I noticed that gives absoluetly nothing to a faction.  While the beam pact isn't amazing for TEC it does kick up their starbase dps a nice bit and adds a little to the Kol as well.  The psionic surge has always been a bit weak and are basically psionic missiles so that would at least give them *some* kind of bonus instead of zilch.

3.  It's a bit too easy to get cease fires going, a little higher threshold would be a good idea.

4.  Destroying entire fleets and wiping out whole worlds really doesn't seem to bother the AI very much at all which seems a bit silly.  Negative military points should add up a lot faster.