oh dear, it sounds like your little girl is becoming a teenager. If you find the solution to adolescant insanity you will get a nobel prize.
I remember when I was a teenager how frustrating it was to still be treated like a child when I felt I wasn't. Maybe you can try to find a way to renegotiate some boundries in a way that acknowledges that she is growing up but is still satisfactory to you.
ie her bedtime could go back to 9.30 or 10 (maybe you can think of another couple of privledges) but if she can't show maturity by respecting you and her siblings and doing her chores without complaining then you will put it back to 9 (or can the other privledges).
In terms of keeping her room tidy I was watching Dr Phil yesterday (daytime tv, how embarresing!!) and he suggested that if kids won't tidy thier room you tell them that you will be inspecting it at a certain time (1 hr away, 9am every morning) and anything that is not in the right place is yours and will be donated to charity or confiscated for a week or two.
Dr Phil yesterday was all about bad kids and he had heaps of tips. Maybe you could check his site for ideas.