If users are given reputation / points / whatever for questions and answers, this would just bring us back to the problems discussed in the reputation thread. I would, however, support a tiny (largely hidden) privilege to allow you to contribute on “protected” Q&A’s (something like just needing to have at least 3 positive-voted answers on the site).
I would propose limiting rewards to moderating (editing, closing, reviewing, etc.), but it’s pretty vital to have proper validation in place so users don’t just robo-edit or robo-review. Maybe the number of reviews for some user can be shown together with the quality of those reviews, or something like that. This can get very complicated, so maybe such rewards shouldn’t even be in the MVP at all.
I have been thinking about a bounty system to reward amazing answers (as the only way to get reputation). But where would the bounty come from? Perhaps we could use the moderation reputation, although being a trusted moderator doesn’t mean you know what a good answer looks like. Or perhaps each user could have a hidden pool of points obtained through upvotes that could be awarded to other users as bounties (similar to regular reputation on Stack Exchange, except separating reputation obtained from upvotes versus bounties). I say “hidden”, but it might be useful to tell users they have at least 10 points, for example, so they know they still have some to spend, but also to prevent it from turning into the thing to game instead. This might just circle back to the same reputation problems, although, if implemented correctly, it should be much harder to obtain, making it a much more special reward and harder to game. Just some random thoughts…