Cara is, fail none, the mouthiest dog I have ever had. I had a Rottie, Mukat, who didn't at all apply pressure but just wanted a body part in her mouth. She never got over that desire and she lived to the ancient age of 13 (most rotties gone between 8 to 10). That said, because she never applied pressure, we never resorted to any harsh response because she only did it to my husband and me and we didn't really mind that much.
Then came Cara… holy hannah. Anyway, I called Debbi (BRAT) and told her if I died, we had a problem because few homes would understand that her mouthiness isn't aggressive. I could stop the behavior, but I just called a friend who also won't mind and will take her, lol. In all situations, someone gets trained and Cara has trained me to love love love her mouthiness. She will hold my arm/hand/thumb in her mouth, massage it with her tongue as she goes to sleep.
But IF I decided to be a better owner and stop the behavior, the only real response is to be a tree, not move, not respond other than NO TEETH and slowly extinguish the behavior. Some recommend things like spray but most dogs... basenjis in particular... learn to find another body part. You can't bathe in stuff. Some dogs you can stop using a spray bottle. I suspect that would rev Cara up, not stop her. I have used NO/ignore when Cara applies pressure, so she has learned a very soft mouth when mouthing me. That said, of course that means if I were a better mom I'd teach her no teeth period but... did I mention I rather enjoy it? It makes her so happy.
If ignore doesn't work, walk off immediately.
As for the cans, you have to set him up constantly and the moment he starts for one, give a loud firm NO CAN and remove him from it. Eventually he will get it, but it may take a while. With all training, if you consistently prevent a payoff every time, they do get it.
Because of my dog breeds (Chows and Rotties), the leave it command is the most important one I teach after come. If you work on this with many things, you should be able to transfer it to cans.
As for hormones, lol, the major hormones come in between 5 to 7 mos so I am sure that is some of it. But his health waiting I feel is more important than trying to cut off the hormones by neutering, so am glad you are waiting. A lot though is simple maturing. Consider this the terrible 2s time. He's trying boundaries again. Dear spirits, that mischievous look right before sleep says it all! LOL they are cute so we don't kill them.