but that might end up being unfair to the older members since someone who joins midway through might only have to vote on 10 applications, compared to the 20 an older member might have to vote on to qualify.

Yeah I thought about this but I figured that giving a new person a break on their first game might actually be a good thing, since they're a newbie and the lower difficulty only applies to their first game -- the next game they would be on the same playing ground as everyone else. On their first game it would be easier to earn the bonus but they get less points for it. An older member would have more work cut out for them but for a larger bonus at the end.

I'm okay with lowering the percentage, if you like.