When quilling ends you can end up with a completely different hedgehog its not uncommon however I think he got accustomed to his old surroundings and now the new surroundings are alarming to him and he is defensive and scared.
He now contends with new scents, sounds, and an entire change in environment which may take him time to get used to.
Hedgehogs bite for multiple reasons:
Defense (Usually Last)
Fear (Part of Defense)
Senses a Threat (Again Defense)
Some hedgehogs like flesh I have a girl whom I still handle often I just got used to handling her differently and hiding my flesh from her and she lets me pet her.
As anything change on you?
Detergent on Clothes?
Hedgehogs are very sensitive and the move can be more stressful of one then the other. My suggestion is treat it like its day one again and keep in mind the biting issue, it may dissipate it may not.
If your hedgehog bites you do your best not to pull back or react it might convince him that biting does no good if he is doing it because he feels threatened. It can also hurt your hedgehogs mouth to do so and I know its hard not to react trust me.
It may take a lot of time but he may go back to how he was or may not, I would hold off on the roommates it might stress him more and adapt your handling and bonding time to his new personality, he may return to how he was and he may not. Either way he will still be a hedgehog you'll love for all his quirks
Also for dry skin get a humidifier to increase humidity it can really help with dry skin.
Flax Seed oil is very successful as is Sunshine Factor and Booster for dry skin.
Its also possible he is aggressive because something is wrong and he is ill and hiding it, hedgehogs are good at this and obviously a hurt animal even if you can't see it is more defensive. A vet might with hedgie experience might be able to find something wrong that might get him back to normal if its something bothering him or hurting him.
IS he still losing quills and if so are new ones growing? Is he scratching a lot mites can make a very grumpy hedgehog
Also what is the temp exactly?