PRECEDENCE presumably has something to do with how highly ranked they are, I'm trying to figure it out myself.
CHAT_WORTHY I'm not sure about. Determines whether they'll give you quests or not; not sure about if it does anything else or not.
MENIAL_WORK_EXEMPTION will stop them from performing labours as most nobles did in 28.
ACCOUNT_EXEMPT... that either means they don't pay anything for anything, or they're not punishable by law. I forget which. Extremely likely to be the former. Forget that, got it confused with PUNISHMENT_EXEMPTION.
SLEEP_PRETENSION I've no idea about, though it sounds as though it might have something to do with them being bothered by "lesser" people having better rooms than them, unless that behaviour is coded in with the room requirements, in which case it'll probably have something to do with 31 which I don't know yet.
EDIT: Here's an idea about PRECEDENCE: If you have a civver - let's say, a militia commander. He has a precedence value of 120. Now a general comes along - he has a precedence value of 50. As both dwarfs have the same responsibility, which is to say, MILITARY_STRATEGY, the precendence values of each are checked, and the one with the lower value effectively takes over. If, continuing the same hypothetical situation, you still have the militia commander around when the general is no longer available, his orders start to have an effect again.
I need to do some testing to see if this is actually the case or not. It should really work with anything - diplomats should report to the monarch instead of the mayor, etc..