Interesting to see a (reddit) account seller trying to improve the forum.

I think a lot of your stated problems can be traced back to problems with the trust system, specifically from the way trust is displayed by default (DT). My suspicion is that theymos wants to have DT setup in a way that he avoids being labeled a "publisher" in regards to liability for libel. If theymos tinkers with the DT system too much, or if it is moderated too heavily, the courts might rule he is not merely hosting content, but is "publishing" content. This matters because if someone is labeled a scammer via the DT system when they are not a scammer, they could sue theymos for libel, and would do so because he is easier to find, and has more assets than most people on DT (and in the forum).

No one obviously intentionally gets scammed, but there are improvements that can be made upon the marketplace. For starters, there could be merit/rank/activity requirements in order to either start a thread, to unlock a thread (more than x times), or to create a thread with self moderation. This would at least increase the effort a scammer would need to put into trying to scam.

I don't see signature campaigns going away anytime soon -- they bring in the page views that generate revenue for the forum. Signature campaigns ultimately are market based, and advertisers pay as little as they can to get the best deal for them. I would point out that when someone pays to have their ad displayed, they are paying to have their ad displayed to potentially 20 other ads on the same page.

Except for "Lack of new upgrades" everything you are complaining about can be traced back to the trust system.