I agree with the sticker thing, leave it as a positive. He has rightfully earnt those so leave those be, otherwise he might think "well whats the point of doing xyz when mummy will take it away anyway" if you know what I mean.

Teddy is our security item too, we never use or threaten punishment with Teddy unless "Teddy" has done it . This way, again, Teddy stays a positive go to toy that still helps with feeling secure and has no negativity attached.

Our 4 year old tests this one out all the time too. We use time out BUT we use it when we are prepared to fight the issue because time out in this house doesnt mean you go to time out and then Mummy and Daddy do whatever task was asked of you. The toys stay there and then the request is asked again, if its not picked up then back into time out and so on and so forth.

We find though that the rule - one toy at a time - works well. If you want to play with the next toy/item/movie then you need to pick up and pack away the last as we can only play with one thing at a time. If you don't want to do that, then the toy stays out and you don't get to play with something else. Our 4 year old was used to us picking everything up for them, they now to do majority on their own. They also know that if they ask for help nicely then I will likely help but not all the time, but outright refusal or a tantrum, will not get them what they want.