Serious Question!!!

[Mischievous_Purple_1]

My Ball Python, Amadeo has been having some health problems lately. He had a small patch of scales about 5-6 inches from his tail, and a spot of blood dried on one of the loose pieces. We figured he must have gotten cut on something while I was away on vacation. The skin on either side had gotten loose and what looked like an air pocket had developed on either side. After some debate, we took him to a local vet and they said that he likely had an abscess just under his skin and gave us enough Anti-biotic (Baytril) to last him five days, which would hopefully clear it up. About 2/10ths mL every day orally, and he was looking a bit better. He was fine for the first day after we finished his doses, and he wasn't acting any different. I fed him last Friday and he ate fine, though I think the mouse might have been a bit too big. Then the bubbles came back by Monday. He's now on an every-two-days dose of intramuscular Anti-biotics (Naxcel this time and under 0.1mL) and they don't seem to have gone away yet, whereas the oral doses worked after just 24 hours.

My questions are:

A) Is this loose skin and 'water'-filled bubbles (the liquid in the bubbled spots looks like water) really an abscess giving off bacteria, or is it something else, like Blisters Disease? (My Dad looked around to see if he could find anything like what's going on and came up with that.)

B) This doesn't have to do with the sickness, more on the mouse being too big. He's adjusting his jaw every 30 seconds to a minute, making it click. I've only noticed it when I'm holding him, I'd have to watch him for a few minutes while he's in his cage to see if he does it there too. Specifically, he's adjusting the right side, the left doesn't seem to be bothering him. He doesn't seem too irritated, and he doesn't react more then trying to pull away when I try to look at it (which he does anyway). Could he have hurt that side of his jaw eating and how can I fix the problem if there is one? The mouse was a decent sized adult, and he's handled two others of the same size with no problem before this, though they were both just a little bit bigger than what I normally give him.