What commonly happens is that you hit 30% likability can get a trade alliance, and then wind up killing a trade ship without realizing it because you can't get a cease fire until 40% to 50%.
Trade ships in interplayer trade routes are invulnerable. What you just said can't happen. It never happens. Why so many people keep claiming it does is baffling to me.
No matter how much i give the AI money, metal or crystal. He will not agree to siege fire.
Are you paying attention? You don't just randomly give it money etc. You complete its missions. You only need to give loot to it if that's what it's asking for, or if you're trying to give one AI an edge over another. This is not like most 4X games where you simply buy the AI's alliances, and they stupidly follow along even though you can and will break the alliance the moment you want to. In Sins the AI is just like you - it's allied only as long as that is to its advantage.
The fact that the AI acts more like a human should be a good thing. It's not perfect, and I hope there will be a boat load of tweaks, but I'm a little sick of players whining just because they don't have complete control over the "diplomacy" as they do in most 4X games.
I mean, look at what the OP actually wants to do: make the AI play along peacefully until the player is in an unbeatable position, so he can stomp the poor bugger - something that even the stupidest human player wouldn't fall for. In most 4X games you can do just that, becuase the player is the only really active diplomat. In Sins you can't. That's a GOOD thing.
