I hope that you've found some ways that work for you and your daughter. I agree with a lot of what the other mother's have said. I too recommend the Love and Logic books. Their techniques work because they help you stop the war between you and your daughter.
Another idea not mentioned is it will also help if you find a way to take care of yourself so that what she does, doesn't feel so personal. Know that you are a good parent who is learning new skills. Have pleasant things to think about when your daughter gets obnoxious. That will help you avoid getting overly involved in her misbehaviour.
I've found that to remain calm, confident, and authoritive in a compassionate way the most difficult thing to do. I was so easily hooked into fighting with my daughter and becoming angry when she wouldn't listen and obey. Your daughter is strong willed and learning how to be independent. She thinks that she knows best and the two of you are engaged in a battle of wills. Mothers always lose those battles.
Sending her to school in her pjs is a great idea.
If she doesn't want to eat, OK. She'll eat when she's hungry. You decide when food is available. Ignore her efforts to get you to do what she wants when what she wants is inappropriate. If doing what she wants is appropriate but her way of asking for it is not, tell her how to ask and reinforce that good behaviour by doing what she asked.
Remembering that you are in charge and that you love her at the same time might help you remain calm and matter of fact. What is happening is not a personal attack on you and your authority even tho it feels that way. She is learning how to control her environment. You are teaching her what works.
To teach her what works means not responding to the negative behaviour but also setting up situations in which you can do what she wants. Help her have success. Show her how to ask for things and allow her to say no in other situations. Spending more time with her having fun might be helpful.
It will help if you can disengage before you get upset. Give yourself a time out. Go to another room, turn on the TV, whatever helps you to keep your cool.
I recommend trying to completely ignore her rude
and defiant remarks in a way that shows she hasn't hooked you. I've been told in parenting classes that if you can calmly and consistently ignore a behaviour it will eventally quit. Never react to the remarks. Deal with the other behavior such as taking her to school in her pjs or putting away the food with the comment that it will be available at the next meal. I wasn't able to be consistent in ignoring my daughter's remarks and so it didn't work for me.
And never argue with her. This has been a difficult one for me too. And with my daughter I learned that when I did too much explaining of why she should or should not do something I was inviting her to tell me that I was wrong. I said I would never say, "because I told you to," but that is a useful phrase in many situations. Other useful phrases are "because it's the rule, because that is what we do in this house or at this school, or while at the store, or in order to get something else." If you want to discuss the reasons for it later in a calm conversation OK but stop the talk if it becomes argumentative.
Raising a strong willed child is very difficult. It is easy to slip into constant battles. Try to inject some humor into the situation and plan for fun together. That will help all of you.
And remember that nearly all that you're dealing with is not life threatening. Learning how to manage our feelings and our actions to get what we want is much more important than getting dressed or eating at that moment. Once you know how to make a positive connection with your daughter and how to consistently enforce the rules in an unemotional way these bad traits will go away. Others will begin as she grows but you will have the basic skills and the mutual respect to cope with them.
I also think that it helps if you let your daughter be involved in making some of the rules. For example: You want her to go to bed at 8 but you can involve her by giving her the choice of bedtime at 7:30 or 8. She is more apt to be co-operative if they're her rules. This will be even more important as she reaches the teen years.