In reply to Ed.

forum points don't accurately reflect someone's coding abilities though, just how active they might be, unlike the point system on stackoverflow etc which is far more of a combination of ability and activity. but nothing like this is going to indicate how well someone has created a theme itself.

for themes submissions, a simple user meta flag (or count) indicating the user has a previous theme(s) that passed review could work though, if it would allow them to (somehow?) put new themes online sooner, at least in the trust that they will not do anything dodgy to put their other themes/reputation at risk... and it means they at least familiar with the review process themselves having gone through it before, those themes are more likely to have less problems from the outset.

and/or, since the entire review process is openly published anyways, there could be an option to just check a box saying "I have self-reviewed my theme and to my knowledge it passes all the required review tests."
This in itself could give enough pause to authors to reduce the number of themes submitted that are just plain going to fail as they are not ready yet.