I think that your ideas are good. My biggest concern with opening the gates was probe abuse. I like your solution. If we can figure out a good system for rotation at level 4 then everything should work. My only question about rotation is that the probes love to talk to people, and if some of their regulars are rotated off for a week, then they may get upset. (Just my $0.02)
If this is acceptable to everyone here, its got my vote.
Toasted