Re: OOC
IDK. The problem is that even if you allow, say, one person to fight a monster all the way through in the time it takes the other person to exchange one blow... well either someone's on at the same time as you or they aren't. If one is and one isn't, you'll have one person doing a dozen posts in the time the other does one and it'll come out really uneven.
Another solution, I suppose, is to let players "queue" actions before they log off to be done after the other the next time the GM is on and either the other players present are on or they've all left queues. Works fairly well as far as playing goes, but it's mediocre as far as reading goes. Better if at most all but one player can leave a queue, I suppose.
Other then that... you could let people "automate" their character during fights. (I mean, it's mostly "I hit them with my INSERT_WEAPON_OR_BODYPART" plus a little flavor. Maybe the occasional run attempt or re-picking-up of a weapon.) Not as good as exchanging posts from a playing prospective, but unlikely to be many complaints about mishandled characters if nothing else changes... and better then the previous option from a reading prospective.