That's the cooldown I was talking about. The RDM hits 41 white/black mana and uses a cooldown to double the mana accumulated. Not-Holy adds 21 white mana, and Not-Flare is speculated to do the same for black mana. If I were to hazard a guess, those two spells will probably be locked behind a requirement; requiring a Cross Cut => Chant du Cygne => Millionstab combo, requiring you use the jump back, or requiring you to spend X amount of mana (though the chances of the last one are very low).
I only brought up rotation because the rotation is the result of what abilities a class has. When the bulk of your abilities are ranged spells, and the devs show nothing but mechanics that involve ranged spell casting aside from grudgingly putting the sword to use for 3 GCDs...the writing is on the wall. You'll cast like a turret until you pool enough mana to do your three hit combo and back to casting you go.
I wish I were wrong, but as I said in the other thread, the devs have had plenty of opportunity to prove me wrong, and have not.
And at that point I ask, why Red Mages? If you want mages that don't use swords making peace and joining forces, Sage would have been a much better pick. Make them ascetics focused on balance in everything to create something bigger/better, and go from there. It'd even conceptually fit as a magic counterpart to MNK (who have the light and dark chakra thing).