I wouldnt make main factions (aka, all faction that have LLs) be enemies. Neutral is good enough. We want to be able to confederate and get all LLs under our control.

Good Point, as the Player wants to confederate,yes.

so, im not expert on warhmammer lore but i read up on it a bit. Alarielle is a lover to tryion and beloved by all high elves, being thier queen/pope. So she should get diplomatic bonuses between Tyrion and Alarielle, and Alarielle to all High elf factions. Teclis and Tyrion are brothers so they should be very friendly. Mazdamundi has saved his race from choas a few times, in lizardmen society slaan are extremly respected, also he's the eldest alive now. Thorgrim is high king of the dwarfs, and orion is a literal demi-god along with being king of the woods so extremly respected among wood elves. these are just the forces of order and thier respect for thier leaders.

as i said someone already put all the values and the reasonings and lore behind it into a mod "Loyalty to the leaders of the elder races." so that should be a good guide for you :)

i wouldnt worry about the forces of evil, CA seems to have to done those right. i noticed as i was playing choas the beastmen were quite friendly and happy to burn down the world with me, Ca didnt seem to get the forces of order as correct though.

For the empire I would suggest getting rid of Wissenland's and Stirland's aversion to Reikland. Both provinces were actually very close allies with Reikland, especially Stirland. I would consider adding a harsh aversion penalty to Middenland though. Toddbringer hates Karl Franz and felt that he should have been the emperor. Also there's the whole cult of Ulric vs the sigmarites. I think that would make the start of the campaign as the Empire more loreful and interesting.

Also, Argwylon should hate just about everyone except the other wood elf factions. Durthu is hellbent on killing pretty much everything not having to do with the forest. His relationship with the elves is shoddy even.