Questions about Diplomacy

[neomax]

Can I offer an proposal such as: You give me the Ice colonizatation tech, while I will declare war against your enemy? The AI always demands me to declare war to or break treaty with his enemy. I can't find a suitable counter proposal.
Another one is probably a bug. When I directly refuse an AI treaty proposal, the relationship will be damaged. However, if I counter-propose a treaty which is already active between the AI and me, it will gladly accept it, and it seems that the relationship is somewhat improved! Can anyone explain this? Thanks.

[Atrocities]

I am afraid not. You can offer to trade a worthless unclaimed planet and system held by your enemy for the ICE Colony tech.

Or design and build several basic ships and trade them to the AI for the tech.