Punishment vs. Natural/logical consequences

[Dandelion]

Since we are still very new to GBD I am still having a really hard time figuring out this whole concept. I keep thinking in punishment terms and it is clouding my ability to tell if I am punishing or if I am allowing natural or logical consequences. And since my immediate mental reaction to a kid related problem is to want to punish, I just end up confused and more angry by the time I actually figure out what might be a logical consequence. I think that I am still being either punitive or permissive most of the time. I am confused!
Here are some examples and how I handled them...

1. The kids are beating each other and screaming over a toy that they both want. This usually involves the 2 and 4 yr olds, but may sometimes involve the oldest. Unless I can clearly see that someone has been wronged (the toy was directly grabbed out of one child's hand by another child, or it is a very special or new toy), I have been just taking the toy and saying that we will not play with anything that is going to cause problems between people, the other person is more important than the need or desire to have the toy.

2. The kids know that dinner will be ready any minute, they have been told, they have washed their hands and can see that the table is set. They are, however, in the middle of building with their Knexs and do not want to stop when the food is placed on the table. So after I have told them 3, 4, 5 times to sit down and they continue to tell me to wait/ignore me, I tell them that they may no longer play with the Knexs after dinner. I think that I did also warn them while saying for the second or third time that it was time to sit down at the table. I feel like when I say something like this, though, that I am threatening them.

3. While we were eating out the other day my 4 yr old discovered that I had ordered him lemonade instead of root beer. He started screaming so loudly that the entire resturant could hear him "You never listen to me! I said I wanted root beer! You never listen to me!" over and over and over and he was crying and really upset. I had no idea what to do. It was very frustrating. Eventually I told him to get up because I was going to take him to the car and then my dh came and told him that he could have a refill of rootbeer after he drank the lemonade, then he calmed down, but I completely don't feel like we handled it right.

4. So finally I will say that all 3 kids have just had terrible attitudes lately and have been screaming at each other and me and dh and anyone else who comes near them. What do I do with a screaming, kicking 2 or 4 yr old? Often the things that cause the screaming are, in my mind, ridiculous. It feels like they are just making things up to scream about - especially the 2 yr old. And I often cannot pick her up, which may or may not work, depending on the instance, because we are in a hurry to do something (ie. get the oldest to school or meet someone somewhere). I also just won't pick her up because I am just not going to put the baby down every 10 minutes and interrupt him nursing again. She has been screaming all the time and I feel that I need to just draw the line and say no more screaming!