This does not sound out of line to me. Labs love to rough house!
My rule of thumb is, if it's not cute/fun/safe with a 90 lb dog, it's not cute/fun/safe with a puppy. Mouthing, biting, jumping are the things you have to be careful of. Even then, when they are a mature, respectful, well-trained adult, sometimes I let some of these things make their way into play or training as long as I can train it the way I want it. But with a puppy, you just have to have hard, fast rules that you relax later, depending on the dog.
One thing, when he shoves into you, if the result is a play fight, he will figure out shoving self into mom = play. If you are OK with that, I don't see the harm. But if you're not, you're better off ignoring the shoving by stepping away or by getting up (if you're sitting) and walking away.