To answer your second question: Yes there is a way to add more kissable people to the game or remove ones you don't want.
However this relies heavily on the lua scripts which I am still in the process of working on and I just finished up with taking a break on them in order to concentrate on some things on the home life side of things since I just needed a break from modding.
I am going to work on adding some things into the game via the lua scripting and see if I can get some guides hashed together that explains how to do all of this.
The lua scripts however are still largely unfinished with testing, error checking and rewriting missing code so I will be getting back to work on that. Once I have the scripts finished everyone will be able to mod the game completely however they like and make almost any mod via scripting that they wish.
As to your first question: I am not the best person to ask regarding this since it is not my best area of expertise regarding bully....lol.
My advice to you would be to read the modding tutorials over and make sure you have done every step correctly and not left out somthing or made a typo of some kind, since changing fighting styles for npc characters is the same process as for jimmy. You need to make sure that whatever fighting style you change for one character is mirrored by taking that character's former style and moving it to the character you have copied the fighting style code from.
Hopefully that makes some sense.....if not then I am sure others here will help out.