I think it would be nice to focus on attracting young blood into mapping, so i'd suggest to avoid setting requirements on what to/not to make as long as it's within the realm of playable ZE.
I'd also suggest at running it somewhat short with smaller projects in mind. I strongly believe that dragged out projects tend to get easily procrastinated and/or scrapped completely.
Keeping it simple, short and juicy should hopefully incite more people to join in.
If you're interested in trying it out, i suggest checking out this site:
The 100% anonymous thing to prevent bias sounds impossible to maintain as people will probably see who the mapper is based on the design itself.
Also, if a mapper is to ask for help on things it would just make it harder to keep it a secret. And what if it's revealed who the mapper is? Does that mapper get disqualified?
All in all it feel a bit too cumbersome for its cause.
If a map is playable and gets added to the server you get the mapper-role, right? That alone is a pretty neat reward as you get a free slot on the server.
(though it would never hurt if anyone would like to throw in something extra to attract more people )
Don't worry about my man-nectar @hotEvercLear, i'm busy working on my current projects so i'm pretty sure i'll stay clear from participating.