[3C][GUI]Diplomacy/Treaties

I don't understand the treaties diplomacy window.

I hvae 3 options: Tech, Trade and Non aggression. Each has a perceived value.

If I click tech on my side (4) and tech on the other (6), I can't make the deal.

I cannot add other deals in the same transaction. In particular, I cannot control-click deals to add new deals.

I can add some gold, but this seems pointless since I'd rather see gold per turn rather than lump-sums.

I can select the other side's gold and propose 2 gold despite his having a -189 gildars treasury. This ends up with a -189 gildar appearing in his part of the trade window. This shouldn't be possible.

Overall, if I get the intent of the GUI correctly, we can select a single trade and have to use gildars to balance the deals.

I think this is sad, since in this case, my partner values Trade and tech in his favor but NAP in mine, so we should probably be able to strike a deal of the 3 treaties in a single operation rather than 3 operations using up some gold.