race map is not available outside of the event channel, and only staff members can create rooms there. The same goes for special tags (RTD, G0~300, S0~300, J0~300, SNO, RVO, SGO, NI, NG, NS, NC, NR..)
supermario cant be removed from race IMO, its existed there for years and it contains everything you need from a race map. More maps wouldnt hurt though (not skillmaps).