S.F.
A.,
I have a 3 year old and she is doing the exact same things. I really thing its just the age. The are looking for ome stronger guidelines and some independance at the same time.
My daughter is a good kid for the most part and wasn't really all that bad at two. I am thinking maybe she is making up for it in the number 3.
You might have to just get a little more restrictive on her right now until she calms down some.