I think curators should be paid exactly the same way as witnesses would. It be a lot more competitive because no knowledge of tech would be necessary. People could also comparing for support and hopefully would see success based on how much people like it. Most people agree he rewards aren’t fairly split, so the people who had the widest variation of users and the best content would likely be upvoted to the top. Of course there could be gaming done, but it wouldn’t be any worse than the top 20 witnesses voting for each other and there’s has been discussion among them to curb that behavior.
Your idea sound a like a good one but it sounds like it’d be a much bigger change to the platform and require a lot of thought.