Lol ok so I've been playing Oblivion for a while now, and for the first time today I decided to get someone to dislike me down to 0 and to my suprise he attacks me along with three others!! This happened in the Roxey Inn.

Yes, that can happen! It depends on their aggression I think. I remember I kept reloading the Whodunnit quest to see all possible dialogue options (There are a lot!) and I set my personality to 0 to see what they would say if they hated me... and it didn't work out well since Nels the Naughty pretty much attacked me before I could do anything, lol.