[Master Belisarius]

Some observations about the AI behavior (please remember that I learned with the old trial/error method... then, I could be wrong in some of my comments).

Looking into the Anger.txt, exist a lot of options, that determine the way, when the AI get or not angry.
I will comment a few, because others are more easy to understand.

1) Receive General Message := 0
IF the race that have the treaty with you, have something more than 0, they will get some anger, every time that you send a general message.

2) Per Ally Ship := 0
IF the race have something more than 0, they will get angry against you, depending your number of ships (Number of your planets x Ally Ship Anger).
The same thing but with the "Per Enemy Ship" parameter.

3)Per Attack Location := 0
IF the race have a positive value, they will get angry against you, depending your number of planets (Number of planets x Per Attack Location anger).

The other important file is the Politics.txt.
Some interesting parameters are:

1) Highest Allowed Treaty := Partnership

It mean that eventually, some races never will accept a high treaty. They don't care about your efforts to have a better treaty.
For example, the moded Version for the Sergetti, have the Trade Alliance as max treaty.

2) Turns Since Last War Before Friendly Treaty := 30

This is the min number of turns, before accept any kind of treaty, after a war declaration.
It mean, for example, if other race send a "Communications Mimic" to your better ally, at least they will be 30 turns without to sign the peace. And if they fell "Brotherly" for you, is not important.

3) Accept Treaty Base Anger Level:=30
It mean that the race will not accept any treaty, if they feel more anger against you, than 30.

4) Accept Treaty Minimum Time From Last Treaty := 10
Similar to the point 2). If for some reason, your previous treaty was broken, they will wait at least 10 turns before accept a new treaty.

5) Break Treaty Base Anger Level := 50
IF the anger for you, is more than this limit, they will break the treaty with you.
BUT, also mean, that the AI could be MURDEROUS with you, and still keep their treaty, if the limit is high.
Also, exist other parameters related with the size of both empires, that the AI use to consider to break the treaty with you or not.

6)Declare War Base Anger Level := 100
The same thing than the previous point, but they will declare the war against you.

7) Max Anger Level for Accept a Gift :=80
It mean that not all the races will accept gifts from you.

Exist too much parameters to comment here, but, are not hard to understand if you check a bit, both files (anger.txt and politics.txt).