Barking, biting puppy

[Tazette]

We've had Sprocket for just over 3 weeks now, we adopted him from the Hay River SPCA, and to our knowledge, his litter was well taken care of, always around other dogs (cats & ferrets), children and adults. We've taught him to sit, shake a paw (and the other paw), stay (we're still working on this to the full extent), rings a bell when he wants out (not 100% of the time and often for attention right now as well), he knows he has to be calm in order to get his food, leash, attention, etc.

Currently we've got a board up between the kitchen/living room and kitchen/porch due to peeing on carpet a few times and to make it easier for clean-ups in the kitchen if he does have an accident. He learned how to climb the baby gate to the porch, so we've doubled up the baby gate and he's just recently learned to climb the board separating the living room and kitchen.

Often my husband and I will tell Sprocket "down" when his paws are on top of the board (because climbing over is the next step) and once he's down, we'll ask him to sit. I admit he's a pretty good pup, but it seems often he'll either bark or growl (it's a cute purring type growl) at us when we're asking him to sit, or try and snap at our face when we're sitting at his level (not towering over him). I don't think he's being aggressive, as he's usually waging his tail as he's doing it, but we'd like some advice on getting him to stop. I'm not sure if it's jut a phase and he's testing the water, trying to up his rank, but I hope is passes soon. We don't laugh at the time of when he's in front of us, but inside, all we're thinking is he's telling us where to go with our "sit" command.

We're also trying to rid him of his biting phase, those little teeth are sharp. He's only 11 weeks old, so I'm hoping it'll pass soon.

Thanks.