The two things still throwing me off are:
1.
Quote:
...Corruption resistance protects against spells, spell-like abilities, and special abilities
as far as i know special abilities include extraordinary abilities like favored enemy.
I do however see your point regarding the ranger's ability stems from familiarity with said creatures rather then something inherent to their evil nature/alignment.
it's not conclusive, but i'll probably follow your suggestion.
2. as far as i know, if i pick Outsider for my bane weapon/favored enemy i can choose Outsider(evil).
actually Outsider(Devil) or Outsider(Demon) isn't even suggested as an option in the PRD while Outsider(Evil) is.
anyway, thank you for replying.