The attitude file does control the factions respect towards jimmy.
However...and a big one...
When you complete the game and are on endless summer, the attitude file is completely overridden by the game scripting and its in two places, scripts.img and the bully.exe.
I may have a way to override some of that since I have explored the exe quite a bit, but have not had time to test out my own findings due to my work on the mega-mod.
At any rate, lemme see what I can do and if I can disable some of this, I will explain it in a mini tut.