Wouldn't it make the most sense to utilize the existing leve system for content like this?

I mean, really. Rarely do people use up all their leves.

(o.0 ) Enter Aurum Vale, use a leve. Enter Hamlet Defense, use a leve. Could subdivide them into different classifications to alleviate crafter's concerns if necessary.

Raid Leves
Non-Raid Leves (cannot think of a good name)

Pick up four raid leves every twelve hours, et cetera. ( >>) Maybe less, maybe more. There are plenty of details that would need hammering out, but it seems a good place to start.