lol....
1.the one that makes a rp map should be really skilled.
2.see 1.
3.40-50 rooms with a prop_door_rotating as entry
4.things like hospital, graveyard, policestation, prison with itelligent jail system and stuff to make the live easier as cop.
5.protections against lags (r_speed skills, knoledge of vis.exe and usage of invisible textures
6.light management
... many other things...