Well, usually only staff members have an out-of-character account. Members can post OOC stuff on any of their character accounts. We have a handy-dandy thing in the mini-profile that tells members who plays that particular character so if you're post out-of-character, others will know who you are.
The only reason staff members have an out-of-character account is so that it's clear to everyone who they can PM if they have a problem on the site who will have powers to do something to fix the problem, and so that administrative posts like application acceptance is kept clean and separate from in-character stuff.