Caster MW is viable 4 sure, great healing, but u dont bring DPS like all the other healers do, thats why u wont be able to push to the top.
But do you really wanna ? Just heal and have fun with your MW Monk . Esp in PvP its the only choice u can really play in shuffle and Rated BG Blitz anyways, cause otherwise u get CCed like hell in meelerange.