Birds are not dogs. They are not domesticated animals like dogs and cats. They will behave and respond differently to domesticated animals. I personally do not advocate hurting a bird to 'teach it a lesson' when it bites. Some biting is caused by a fear response- if the bird does not see a way out of a situation they will sometimes resort to biting to try and make the perceived threat go away.
Barbara Heidenreich is an animal trainer who has a lot of resources on parrot behaviour and training. It may be worth looking up some of her articles and books. She sometimes hosts webinars that you can pay to participate (or pay a smaller fee to watch back a previously recorded webinar). I'd strongly recommend doing some research on positive reinforcement and parrot behaviour before trying anything or letting others try anything. Invoking a fear response by hurting a bird or trying to dominate a bird by trying to be the 'top dog' isn't going to get you very far and you'll probably end up being bitten more often as a result.
On the days where your bird is trying to be independent and do his own thing then your best bet is to sit back a little bit and let him explore at his own pace. Don't attempt to force him to do things he clearly doesn't want to do. If I try and scratch Alfie's head and he's not interested then I know I am asking to be bitten if I keep trying to scratch his head. Body language is key with African Greys- you have to watch carefully at the subtle messages they are trying to convey. The bite is often the last resort... basically a "I've been trying to tell you to back off... now BACK OFF" response.
The red factor means nothing to his health so don't worry about that. Like others have said, what kind of diet is he on? You've done the right thing getting him to a vet, as long as he/she is an avian vet. Let us know what the test results are.
I know how sensitive I am to off gassing. I once went into a new Best Buy and had to turn around and leave because the fumes were so bad, so I totally believe that they could kill one of our birds. I hope the wait till spring isn't too long, but it does sound like your best option.