Also, as far as attitude, we were headed in the same direction and something clicked inside of me about why. DD was ready to take on more responsibilities and because we were still treating her like a baby she was lashing out at us. Once we recognized this and gave her more to do her attitude changed. This isn't to say we didn't have some outbursts here and there but I also made a point of explaining in detail why it wasn't acceptable. I know experts claim children at this age aren't ready and can't grasp the whys of the issue but I found that my DD absolutely could. By treating her with respect and talking to her in a more mature way and by providing options for her to choose instead of what she was wanting that caused the tantrum; she was more willing to accept what was right and wrong.
I whole heartedly agree with this. DD has a lot of separation anxiety and for once we were able to use that to our advantage. We explained to her if she runs away from us in a parking lot or at a grocery store or where ever that someone could take her away from us. She was really calm about it, asked a few questions and then never tried to run away like that again (the final straw was at the airport a couple of months ago when she ran down the corridor leading to the airplane BEFORE boarding had started!!).
We try to explain things to her as clearly and directly as possible. If she doesn't brush her teeth the germs are going to "eat" her teeth, if she doesn't take a bath her butt will stinky (ok, she mostly thinks this is funny), if she doesn't put away her toys they can get broken etc. It's not a perfect system but it has helped significantly.
ETA: I missed your comment about bedtime at first but I'm just wondering if you have a consistent routine? DD was horrible to get to bed for the first 2 years of her life but we've fallen into a strict routine now that has helped. We also sing her to sleep every night (the trick was finding the right song that puts her to sleep) and now she falls to sleep relatively quickly every night.
