It is strange that at my current game

Justian is pleased at Bismack at -2,
But is annoyed at Gandi at -2

How could I know when a civ is gonna be pleased with me or annoyed with me?

Screenshots or savegame, please.

There are a few "hidden" modifiers that don't get shown. Those are what's resulting in different attitudes despite the apparently similar numerical values.

Bh

Could you be more specific?

In the xml file. I see things like Wormonger respect, high rank, low rank and stuff, I just don't know how they affect Diplomacy?