My puppy trainer told me that when puppies bite you, just yelp a little bit and back off of them. If they continue to try to play bite, just face different direction and avoid him for a bit. You yelping a bit will let him know that it's not good to bite and you are hurt.
Humping wise, it's not always dominance issue, but sometimes it's because that they are just too excited. My puppies did this (ofc boys) and I told them *no humping* and if they continue, just say no and correct them. repeat and it should stop. one of my puppy did this early and he doesn't hump anymore.. he's 8 months and not fixed yet. He tried to hump my girl puppy when she was in first heat, (humping the air next to her) and when I told them *no humping* he immediately backed off lol
*the forced relaxation pose* is what my trainer calls when you put them on their belly to relax them. But when you do this, make sure that you are petting him while doing it, and if he moves and you didnt say *ok you can go*, just say *no, relax* and return back to that pose. it may take awhile, especially since he's a puppy and maybe a stubborn yorkies.. (mine was lol), he should also probably let out a small sigh when he's done.. but if you continue to do this consistently, he should learn quick
If anything, look into AKC CGC trainers and they should help a lot