to the site.
I am no expert but I am sure someone with more knowledge than I will be along soon, but will still pass along my thoughts. How old is Bently? The missing fur could be a number of things. It could be allergies related to the environment or food he is eating. It could also be caused by stress, a bug bite or possibly even demodex mange.
As for the panting... As i don't know his age yet not much I can say other than dogs do pant in stressful situations though. My Harlea rarely pants unless it is after playing hard or running around outside for a bit.
Lump under the skin... Again this could be a number of things but I have never heard of a collar causing it. It could be allergies, a cyst, tumor, fat pocket or even a dermoid sinus that is now infected. I would have this checked out by a vet to really see what it is.
Walking on a leash is a fun one we all have to deal with in the beginning. There are a lot of different ways to work on the pulling including using a front connect no pull harness so that when they do start pulling they wind up turning themselves around towards you. What we did was stop walking and gently pull Harlea back towards us while repeating no pull and we would not continue on until she relaxed. It has taken us months to get where we are but she rarely pulls any more and usually the only time she does is when we go to PetSmart or something. The key to any and all training with a bully is persistence and consistency making sure they understand you are the pack leader.