The only situation where an A.I. shouldn't attack you or attempt to beat you is if you'll obviouslly kick their ass.
An A.I. should never sit back and let you reach a point of beating them because you were nice to them. Ever. They're supposed to be our competition. Maybe some A.I. can have a "Well... he was so nice to me this game, I think I'll let him win" personality trait... but it shouldn't be a coded part of the game.
The reason why the modifiers aren't shown to us is because in civ5 they're irrelevant, period. The diplomatic process is intuitive. You give someone some iron, you give them money, you join them in war, you do anything for them then naturally, they might like you.
However it comes with the exact same risk of playing with any opponent. Trying to befriend someone is the equivalent of gifting some of your own resources in the hopes you won't be an active target. It is, and always should be, a
gamble.
Further, coding the A.I. so they actually perform as
opponents or players is the only way to ensure they aren't taken advantage of, because in the previous civ4 design, I, who always achieves a conquest victory, will make nice with X amount of civs and without logic or reason stab them in the back when my superiority is guaranteed. Wait... there is a logical reason;
I want to win the game.
Under a system where modifiers govern the A.I.'s behavior, ala civ4; where certain A.I.'s won't ever declare war on you if they reach a certain status... is completely abusable. It prevents the A.I. from making the same decisions we can make: Being friends with someone for such a long time and then betraying them with the only rationale being that they've become a threat to our win, or the next on the chopping block to achieve our win.
As such, there's two things you can do; Have the modifiers control the A.I. and show them to us.... with which the
former is quite simply stupid. Or; Have the modifiers not control the A.I. and show them to us... with which the latter is quite simply
irrelevant ~ Because we'd never hear the end of "OMG I had +15 with Napoleon but the SoB attacked me for no reason".
Either the modifiers are relevant (poor design, imo) and thus we need to see them... Or they're not relevant at all (great design, as it keeps the A.I. competitive and less of a waiting puppet for the player to control) and thus seeing them serves zero purpose to the player.
I'm going to go out on a limb and say the real reason we don't have the A.I. modifiers on display is because the A.I. aren't
governed by them. Thus, the information is moot.
This is precisely the problem.
I get a message from Alexander saying "don't settle near me".
Ok. What does that mean? Which tiles can't I settle in?
For how long?
If he builds a new city near me, and I settle near that, 100 turns after the original message, does that still piss him off?
Again, I think it's fairly intuitive. Don't settle near him. Ever. The more you do, the closer you get, the more likely you will become more of a threat in his eyes. Why do you need a turn timer? Why do you need a spreadsheet? Imagine you're playing against... Me, for example. If You build near me, you risk becoming my opponent, like any other player. If I say "Hey, stay away from me" Then obviously I don't want you near me. If an A.I. says this, then you settle in a different direction, or you settle in their direction, becoming more and more prepared for a confrontation the closer you get to them. It's pretty simple. "Stay away from me" means stay away from them. The closer you get, be it 20 tiles away or 10... the more likely they're going to consider you a threat and/or want to attack you.