I'll reiterate here... Huskies are not off-leash dogs. They are not bred to be off-leash. They're bred to be on a leash and pulling a sled
It's important to practice and train recall if you can, but a husky (even a husky mix) that is displaying the signs that you are describing will NEVER be trusted offleash. If that makes you that more determined to find some "magic fix" then he's probably going to end up lost or injured. There isn't a magic word, or a fix... it's the breed and that will not change.
Huskies are bred to be intelligent and stubborn. They absolutely have selective hearing and will listen only when they feel like it. Think about it-- the lead dog in a sled team is supposed to be smart enough to refuse a musher's commands if those commands will lead him into danger. If the musher says to continue forward across a frozen lake that is not safe, the dog is bred to refuse this command. This doesn't really encourage obedience
There needs to be a purpose behind the command and it takes a lot of patience, rewards and consistency in order to accomplish it.
Mouthing is something I meant to write a sticky on... haven't gotten to it yet. Huskies are notoriously very mouthy. Again, consistency is key, but you need to nip it in the bud now. Anytime his mouth makes contact with your skin, try giving a firm "NO!" and then getting up and walking away. You need to completely ignore him and it's usually helpful to shut a door behind you if you can. If he can't behave appropriately around you, he loses the one thing he wants: you and your attention.
It sounds like you have a handle on the jumping... but to add to it, again-- do NOT give him attention when he jumps. If he jumps, put a knee out to barricade you, turn your head and face away until he calms. When he's calm, THEN give him attention and praise. It's a matter of catching the correct behavior and praising.
It sounds like even though he's getting a lot of exercise, it may not be enough... you can try mental stimulation games with him too. Try "Hide the Queen" with a treat and three cups. Shuffle the cups and make him find the one with the treat. Obedience
training like sit, down, stay, etc will also give him stimulation, but only work in 20 min intervals: any more and he will get bored. The trick is being patient and calm. He'll feed off of your energy. You might also need to find a high value treat. We use jerky-type treats, but you might be able to use cooked chicken pieces, bacon bits, hot dog or sausage. Find something he goes nuts for and is willing to listen to receive.
Last but not least, I wouldn't whap him on the nose
Nose popping can cause more harm than good. Yes, reflexively it happens if he gets to mouth you when you're not expecting it, but in any other circumstance, I would highly discourage it.
I would start using Nothing In Life Is Free
training with him (and Boone if you like!). It's a GREAT method of establishing your roles in the household, easy to maintain/upkeep, and really works wonders. Google it for more information- there's a ton written on it for free on the net
I know that was a lot, but I was trying to respond to as much as I could! Please ask more questions if you have them. I hope this was helpful and welcome once again!