Actually I made some mistakes in strategy of this game, now I play in 1912AD and I have make 5 wars end. But because of those wrong strategies I think I can't stop wars by UN from now, and my technologies also very slow. I will play as Canada another time if possible.
Okay, good to know, I think if 5 peace deals are possible by 1912 then 12 might even be a reasonable number, but 10 definitely works.
Yes I received immigrants. But only 2 or 3 times from 1866 to 1912(40 turns in Epic), turn to Canadian culture immediately, but I think I don't find GPP increased by immigrants.
I think I will make the mechanic prioritize NA more, part of the problem seems to be that there are now a lot more potential target civs.
Why aren't the success chances displayed? And I assume there are more options if you have even more spy points/gold that just weren't visible for me, it would be good to have those displayed (greyed out) as well, to just give the player an idea that there are X costlier options and thus his "cheap" option will probably fail.
Displaying the chances is possible. Not sure if I can also add inactive buttons, the Python interface is kind of rigid in these things.
Also do these options only pop up if they are about to vote against me?
Not necessarily about to vote against you. It always depends when their decision is up to the random number generator. I think the flavor text reflects that ("Germany is undecided ...").
To be more precise, there are two factors that influence an AI decision: how much they think you deserve the city ("claim validity"), influenced by stuff like stability maps, your culture, proximity to your cities ..., and how favorable they are towards you compared to the owner ("favor claimant" and "favor owner"), influenced by diplomacy and other factors such as their own desire to expand there.
This results in five possible scenarios:
1) positive claim validity and favor claimant + claim validity < favor owner: they think you have a valid claim, but favor the owner so much over you that even the claim can't overcome it (vote no)
2) positive claim validity and favor claimant > favor owner: they think you have a valid claim and favor you over the owner (vote yes)
3) positive claim validity and favor claimant < favor owner: they think you have a valid claim and favor the owner, but your claim is good to overcome their favor of the owner (the previous two cases have already been ruled out). So their behavior is random (better claim means better chances though) and you can increase the probability by spending gold or espionage (votes random / based on bribe success)
4) negative claim validity and favor claimant + claim validity > favor owner: they favor you enough to overlook your bad claim (vote yes)
5) negative claim otherwise: you have a bad claim and are not favored enough (vote no)
edit: holy crap, I get a -4 diplo modifier for failing that? Oo
Does it decay quickly?
Like normal temporary modifiers (such as from events). You're right that -4 is probably too harsh.