I have never needed to alpha roll, scruff, muzzle-grab, etc any dog. I DO think that in VERY RARE, extreme cases, a dog can and should be alpha rolled--but again, RARE, EXTREME cases. Virtually any behavior problem can be solved with positive methods. Rusty is still a progressing dog-aggressive dog--initially used "alpha theory"-type methods, but quickly switched to positve and he's improved in leaps and bounds. I don't have to alpha roll him, scruff him, or grab his muzzle and scream in his face. Alpha rolling with wild wolves or even a pack of domestic dogs rarely ever happens unless something REALLY gets out of hand, and with wolves an alpha roll means quit now or you're either exiled, severely injured, or killed. That's not a message I want to send to my dog.
As for muzzle grabbing, with aggression that can be a very dangerous move on the handler's part. Believe me, I have a scar to prove it. With most dogs a sharp, "Aaaah!" or turning and walking away briskly is all that is needed. Scruffing, like alpha rolling, isn't needed that often. Mother dogs will SOMETIMES scruff their pups if they get out of hand--but this is something that a dog needs to learn from another dog in specific circumstances. Again, with PEOPLE it can easily be solved with positive methods.
You DO, in my opinion, need to be the dominant one of the household--but that DOES NOT mean bullying your dog into understanding you're in charge. All that means is that he does not try to take charge in any way. He needs to wait to eat when you tell him it's okay. He needs to wait for you to walk out the door before he does. He needs to follow you on-leash, not drag you on leash. Basically, he needs to be polite member of the family. You do not need to alpha roll or scruff him to be in control, and this CERTAINLY will NOT give you a good connnection with him.
The biting is a normal puppy behavior. All puppies are likely to bite, jump, etc at some point in puppyhood. It is easily fixed with consistency and patience. I would recommend re-reading the thread I linked to on the other post.
Let's take Zeke, for example, my very timid BC/heeler mix. In the past he has had fear aggression issues, mainly with larger, over-friendly dogs. If I were to grab his muzzle, alpha roll him, or scruff him, this would ONLY make him MORE scared. He is not being aggressive out of dominance, but out of FEAR. And making him MORE scared would not solve the issue. This could cause his issue to escalate in so many ways. If I barely raise my voice in an angry tone this dog exposes his belly and shuts down. To alpha roll/scruff/muzzle grab him would be just plain stupid. As a puppy he had separation anxiety issues, and until about a year ago he was constantly trying to get himself in my lap. This wasn't due to dominance, he was not trying to take charge of me. He took comfort in being as close to me as possible and was just that nervous. Now he's just a velcro dog--no longer jumps in my lap, but does stick very close if he's uncomfortable. I'm not going to scruff him for crowding my space or yell at him because I nearly trip over him he's so close. I just work on POSITIVELY boosting his confidence and help him learn that the world away from me is a fun and safe place.
Anyway....my point is I don't approve of or recommend anything like that. You can work through your puppy's nipping just fine using 100% positive methods.