now, i've gotten an offer to let him stay at someone else's place for a little while but i'm not sure if this might be beneficial or harmful. it might be good because there are no other cats but it might be bad because he'll be away from the safety of my bed.
any thoughts on this?
If the move to your friend's place is only temporary, I say try it. Maybe kitty just needs a vacation.
The only other thought I have is, since he used to be so dominant, maybe he has developed an illness or an injury, of which you are not aware, that is triggering the aggression from the other cats; in other words, they are sensing a new weakness in him, and attacking it. You might consider having him checked by a vet.
"There is more wisdom in the song of a bird, than in the speech of a philosopher...." -Oahspe
"The thing is, you cannot judge a race. Any man who judges by the group is a pea-wit. You take men one at a time." -Buster Kilrain, The Killer Angels -Michael Shaara
"Anyone who doesn't believe in miracles isn't a realist." -Billy Wilder
Rather than moving him to a new environment is there any way you can put him in a room separate from the other cats? If he loves your bedroom maybe set him up in there for a while with his litter box and other things. Give him some time there to work through some meds options to see if you can find something to help him? Then, once you get him settled and less anxious you could basically re-introduce him to the other cats.