Karen didn't hate Mara nor did she take the action against the other author's wishes... everything she did was according to the story-line that was agreed to by LA and all authors that took part in the project... there was no personal motive it was simply a plot point they all agreed to that happened to take place during the book in the series she was writing..
kinda getting sick of clueless fans trying to blame authors for things that were approved by people much higher than them...
No she didn't hate the jedi or Mara Jade. I think she just drew the short straw and got stuck with having to kill Jade.
I think her beef with the jedi/sith, was that most books made them all powerful immortals capable of anything. She merely wanted to make them mortals. Why I like the RC books so much when she brought in jedi. She posed moral questions to them and made them actually HUMAN. Actually have feelings, actually question morality instead of taking for granted whatever they said is instantly right.
Put again, this is just me taking a stab at it, I in no way actually know what KT thought or didn't think.