Check here for more info.
Due to a bug or some crap like that you have to pick the option all the time after switching characters, atleast the first time. Maybe its that?
Would kinda suck having to complete inferno first. The game is too easy so why not have MP already at low levels.
OP spells at Ashran? Based on faction population? Yes, WODs gonna be the most awesome expansion ever! Propably gonna hit under 4 million sub mark.
You just need to select it from the "options > gameplay" menu. It's true anyway that swapping characters sometimes make it disappear, just select it again.