The rankings don't mean anything other than displaying how many times you have posted, unless you're a moderator or have been a contestant (or were actually a part of the show's staff at one point, like Scott). I think Gavazzi and Army are the only two members to have achieved "Loyal friend and true" status after surpassing 10,000 posts, but they've also been around since like the beginning of the internet.
How often you post and the 'status' listed below your username are meaningless as far as your reputation among others is concerned. Some of our most highly respected members have lower post counts than those who have high post counts but offer very little in the way of substance. How long you've been a member is also largely irrelevant, at least to me.
In other words, posting just to raise your post count won't get you very far here in terms of respect.
White and green? You're not talking about the icon on the upper left that turns green when a user is online, are you?
Oh, is that what that is?
Correct. A few members here have their profiles set to not show whether or not they are currently active. I believe this feature was once something that could be toggled on or off, but that ability has since been disabled. Those who previously didn't have it enabled or joined after the option was taken away have the online status turned on by default whenever they log in to the site. I believe after 30 minutes(?) of inactivity, the indicator shows you being offline.