What was Kripke's plan?

Does anybody know some ideas that Eric had for Supernatural and decided to change them for this hoặc that reason?

For example, I know that Anna was supposed to do some things that Cas did cause the những người hâm mộ liked Cas better then her.

Jessica was supposed to be evil hoặc possesed.
The hiển thị was supposed to be about a journalist.
John was supposed to appear in DALDOM insted of Lisa etc.

Do bạn know anymore interesting stuff like that? Does anybody know the plans for Bela hoặc Jo (if it wasn't for the người hâm mộ hate)? How season 5 was supposed to end?

Thanks!