Its really difficult to offer advice without knowing exactly all the different types of behaviour she is displaying. But I will give you my opinion based on a three year old who I looked after who was displaying simillar problems.
With this little girl I had to be very clear about the boundarys which i think all children need. clear rules with consequenses and rewards, the key is to keep them small, its completly counter-productive to threaten ie if you do that we wont go out to the tea party and then she does what ever you told her she was not allowed to do and then you go out to the tea party. The naughty step would work in this situation but beware if you are just introducing it it might take several hours or more to make it work the first time, so mabe if you do have to go out somthing which will be easely inforcable ie no bed time story or only one if you are used to reading a few.
Anoter tatic is to try and ignore the bad behaviour and reward the good this can really work well especually if she is throws temper tantrums! I did this once and the little girl got so wound up made herself sick! i just carmly cleared it up and then left her on her own without saying much at all other than i bet you have a sore throught now!
I hope that helps a bit. good luck let me know how you get on.