Agree that it would be better as a passive, completely disagree about toggles. Toggles SUCK. Blizz realized that years ago when they took off the toggles on heroic strike, rune strike, and maul (I think it was maul, the bear druid heroic strike thing). Having played rift which was toggle-toggle-toggle-toggle for the mage class... no thanks.
I'm only semi-okay with toggles on FnB and blade flurry, but that's because FnB will auto end it's toggle when used up, and when you use blade flurry, you have more time to do actions since it depletes energy so fast. Toggles for things like casting on the move are horrible, and even pressing a button for casting on the move sucks. I macro Spiritwalker's Grace into my ascendence macro on my shaman simply because shaman are super bursty, and I'd rather make sure I lose 0 dps during ascendence versus timing SpiritGrace on some movement heavy part of a fight.