So many words here. I read most of it but might have missed a few posts.
Representation
Hazuki is right that we need to define what "representative" is.
If you want "representative" of the "average" user, then just shut the site down right now and redirect users to 4chan or gelbooru. I'm not even being sarcastic. There is no reason for danbooru to exist as a standalone site if the goal is "the internet standard". Let's be honest - the typical user on danbooru is no more sophisticated or interested in the management of the site than the average user anywhere else, which is entirely normal.
The only difference is that danbooru doesn't let those people influence policy. So if you want a site representative of the people who actually contribute and structure things, you're really not too far off right now. And that's danbooru's identity: incredibly precise and well-thought out and complete tagging and good functionality for accessing those images, maintained by a fairly sizable group of people who are explicitly interested in such things.
The second we dumb down our romanization or naming or tag structuring policies, that starts to degrade. And you probably lose your primary contributors in the process.
Promotions
Giving us a way to pick users out more easily is certainly a fine idea.
Barring that, make it more widely known that suggestions are always welcome. But people should realize that the answer will sometimes be "no".
General forum
Adds nothing other communities don't do much better and more relevantly. And it's just an extra moderation burden. You'd have to set some rules (like avoiding political/religious debates, ban huge sigs and massive avatars and other nonense) and then enforce them, unless we just want to have a big cesspool full of bickering and spoilers (i.e. most internet forums).
Stuff for member-levels
If you can increase the allowed tags cap at all, do it. Two is pretty tight.
But it all comes down to what you think the site should be, albert. Are you unhappy with it, or are you primarily reacting to unhappy people who contact you? For every one of those I'm sure there's far more who use the site just fine and never think of it one way or the other.
So, just try to avoid making any decisions based purely on those who complain, because they're always the loudest, and don't always guide you in the right direction.