i would say that Aztec was a pretty good map , most servers run it and it remains populated, as for slots im not really sure but the idea of reserve slots for admins sounds like a kool idea , maybe also make reserved slots for community members that donate? but make them so they can fill if being un-used.

i also think you should test a few maps out first maybe adding 2 more to the original dust2 rotter to see how the public react?