Oh boy sounds like you have my daughter..lol. As for how we deal with her attitude, thats pretty easy and she behaves about 90 perecent of the time when it happens.
If she talks back with the I hate words: Loss of her fav toy for 1 day, no tv or other tv related for 2 days
Talks back saying shut up: Loss of fav toy, no Computer or TV access for games or cartoons for 3 days
Hitting: Grounded from friends coming over for 1 week- 5 days
Fighting with sister that brings in the time 6 min outs, and removal of several of her fav toys for at most a weeks time
When shes the good girl I know she can be she gets to pick out 1 new coloring book, 80 piece puzzle or reading book from the Dollar Store. We see alot more good days lately
Ive noticed since shes started school shes started the mouthing off alot more, And I have asked other parents in her class if their children are doing the same, oh yea its normal. But no less frusterating, being consistant has made alot of improvement but she still has her bad days like we all do. Keep doing what your doing for disapline and you will se change, but Also when they are good praise them for it and make sure they understand they are making you happy when they are good.Also on days shes good she gets a sticker to wear and a gold star on the calender. In her room to remind her.
Good luck and best wishes