Those are good aplicable ideas and it would make for a fair game jam.
But the "only participants should vote" rule would turn it into an even that is folded on itself. Not that it is bad, but it's almost a political choice at this point. And I think it is up to Mark Brown to make that choice as it is, after all, his jam.
Personaly I believe that getting "normal players" to play my games and discuss about it is more interesting than only doing it with devs. Ultimately games are meant to be played, for the players, getting to give feedback is fun and is an incentive to participate. It's more important than the contest that goes along with the jam.