The gold stars simply denote postcounts. Strategists, mods, and site adminstrators get extra stars. In the big scheme of things, postcounts and stars do not seem all that significant, since you can generally tell how reputable a person is by looking at the content of their posts.
I don't think that there are any privilages that people can earn. For the most part, it would appear as though you get just about everything up front. Unlimited attachment space, custom avatars, ability to rate users, give reputation (which I rarely use, since I don't care so much about it), report posts, and unlimited amounts of posts. All of these privilages are pretty nice, compared to other forums (which have limits on postcounts, requires earning privilages with higher postcounts/reputation/karma, and only a limited selection of avatars/sigs).
Mods get the ability to delete, move, and edit other people's posts. Their job is to enforce the boundaries of the forum; it requires a long-term commitment, and often times, difficult decisions (this is what I know so far). Considering that their rights can be badly abused in the hands of a wrong person, only site administrators (WPM, so far) can appoint mods. I don't know why some users want to become mods, other than to be helpful. For me, I have no interest in becoming a mod or admin whatsoever, since I feel that my best role in the community is to voice my opinion, ask for other peoples' opinions, and give/take advice to/from others.
If anything, I feel there may be a little bit too many privilages. I don't really think that unlimited attachment space is necessary, since I delete outdated attachments anyway. Perhaps 100 - 500 MB per user would be sufficient. I see the reputation system and user rating system as being something that can be abused, even though it is nice to have around.
This is just how I feel though. Do you guys feel as though there are enough privilages, or too many?
If anyone knows something about this site that contradicts something that I said, please correct me, since I don't want to be giving out misleading information.