buckling a guy into a bed, blindfolding him, taking his mic, and never letting him out
That would be best described as TERRIBLE roleplaying.
First, security is supposed to be fair, so they shouldn't take a microphone, second, leaving someone cuffed and/or buckling them *inside of a cell* is wrong, although in an emergency they would be tolerable if you can't use the brig at all.
Blindfolding and ignorance is just pushing it too far. Yes, you can leave them in a cell for the rest of the game, but you should at least have a reason. And even if you do, you shouldn't do anything else to them.
<Warning: The following is based merely off of assumptions>
I can see how buckling, cuffing, blindfolding, and removal of a microphone would make sense for interogation, but even then, just leaving them there is unacceptable. (Exception: game-ending emergency and an apology. Also, faking leaving would be a nasty trick. Just open the door and let it close, then sit in a corner. Then a minute or two later open the door again and act like you cam back. The player will be irritated enough, if they didn't just log out, that they will actually consider giving in to your demands to get back in the game.
</assumptions>
Unrelated:
Maybe have wounded players occasionally leave single pixels of blood, depending on how badly hurt they are? Keep an internal counter, so that it will heal? When damaged, set that counter to the minimum of damage level and their actual health(I mean health lost, so on zombies and such that take more damage to kill, it will take longer to bleed, and non-physical damage won't trigger it at all)? Have the player only bleed if that counter was past 50? Only have it at a rate of maybe 1 pixel every 10 seconds, maxing out at 1 per second at the point where they can barely move?