I tell you what needs to be done in order to be a good map.
Have all the map makers join in to make 1 map!
1 person starts off from basic and just build the base, zip it up and upload or send to another person to add designs, send to the next person to add some kind of sound or earthquakes lava, and send it off to the next person.
See where I am getting have everyone work on 1 good map and have all the ideas in 1 that way it can be tested and commented on by others of what they think.