6 month old puppy still biting nonstop, playing rough, and not house trained

We’ve had Beau since the beginning of December and he just turned 6 months old. No idea what kind of dog he is because he’s a rescue, but people have said he might have hound, pitbull, Rhodesian ridgeback, and terrier in him. He might be something called a pot cake? He’s about 30 lbs right now. He seems really smart, loyal, and stubborn. I’m definitely going through the puppy blues…

Anyway, he’s so freaking rough when he plays that I am borderline considering reaching back out to the organization we adopted him from. We did do puppy training classes through PetSmart which he did really well in, but we can’t figure out how to stop him from biting the shit out of us when he’s playing. He’s also started pawing at us and even though I trim and dremel his nails smooth he’s ripping our arms apart.

He is still peeing in the house too. We’ve trained him to hit bells hooked on the doorknob to be let outside, but there are still times he’ll pee then hit the bells. He’s like 90% there, but we can’t seem to get him all the way potty trained. He’s crate trained and has no accidents at night or during the day if he’s in the crate. He’s my first puppy as an adult so I don’t know if this is normal or not.

What tips do you have for either issue? I am considering doing more training somewhere else, but it’s not doable right now schedule and financial wise.