Handicaps: Not working as advertised

Firstly, I only tested for happiness, not other bonuses. However, the happiness bonuses are not working as intended for the AI, so let me elaborate:

Problem 1: The AI uses the STANDARD_HANDICAP PostDefine instead of AI_HANDICAP

Since that is set to chieftain level, the AI always plays on chieftain and therefore gets only 60% unhappiness.

Problem 2: The AIUnhappinessPercent bonus is apparently unused

Or at least there's no difference between playing Deity, Immortal and Prince regarding AI unhappiness, which means the chieftain handicap value is used rather than the AI bonus

Correction: Problem 2 just seems to be a display problem. See below.

I'm not sure how far this extends to other bonuses, they'd all have to be tested individually. You can reproduce this by starting a game, for example on prince, end the turn and then run Players[1]:GetUnhappinessFromCityPopulation() in FireTuner. This will give you the unhappiness for one citizen from your first AI (which is 60 in my tests). Then switch to deity and try again.

problem 2 is disproven.
http://forums.civfanatics.com/showpost.php?p=10160269&postcount=9

i'm curious if problem 1 is intentional or not. i'd assume what little play testing they did was with the AI playing as chieftan, and the AI isn't overly difficult to beat at any difficulty, so it may be intentional.

Seems like you're right. It's somehow applied after what most of the lua functions show. And both modifiers are multiplicative, so .6*.6 = .36