I just popped onto your server I have a question regarding worldedit for players who vote. Is this a time period they gain WE when voting? Because allowing players who vote to use a resource intensive and possibly dangerous plugin may be against your goal of optimizing the server.
Yes, players gain 6 hours of worldedit per vote and there are 4 voting links meaning that a player can gain up to 24 hours. I've got AsyncWorldEdit installed though so I don't really think WorldEdit will be too much of a problem.
It really seems to me you're kind of hitting "the wall". There are a few places to tweak, but I'd personally recommend just setting a player cap at 300 and call it a day.
