I've been and probably will be again in your shoes. Am I too strict ? Will this really help ? I've seen kids getting away with too much as well. The 3's and the 4's were difficult with my girls too. I did and still do what you are doing. I remove the privileges when the behavior is not appropriate. I do however give them a chance to make amends. For example if my daughter was interrupting and whining. I would have simply said " Excuses-me I am talking, your behavior is rude. Now I'm going to give you a chance to apologize and wait your turn to speak. Otherwise we wont be able to get a treat."

But my kids do need to sit at the table until the meal is done, they eat everything or nothing else, the need to say please and thank you, they have some responsibilities like putting away shoes, hat, jackets and things like that.

I don't know if I'm too strict but I know my kids are happy and I'm very proud of them. So it works for us I suppose. So I say keep doing what you do if you believe in it and if it works for you.