Would it be too out-of-pie for this to capture permanently?

Do this and Capture by Force (2) need to specify "if that creature is still on he battlefield," like Auratouched Mage?

"If that creature is on the battlefield" doesn't really make sense here. That creature is guaranteed to still be on the battlefield, since the spell hasn't finished resolving, and we haven't checked for state based effects yet (creatures with lethal damage go to the graveyard).

So, in other words, if you cast this on your opponent's Perilous Myr, you would deal 4 damage to it, gain control of it, the spell would finish resolving, and the Myr would die, and, since you were in control of it, you would deal 2 damage to target creature or player. Since most players wouldn't think of that, I'd suggest switching the order of events, so that you gain control of the creature, then deal 4 damage to it.

The Auratouched Mage, on the other hand... it can enter the battlefield, put its ability on the stack, then be killed before the ability resolved. That's why it has "if that creature is on the battlefield". We don't need players thinking they can enchant their Auratouched Mage in their graveyard. :D

As for too out of pie for permanent control? I kind of think so. The theme to red control is "I was so impassioned, I lost my head." This doesn't really feel like that. I think you could make an argument for that sort of spell being black, however. The idea of whipping someone until they submit seems more up its alley.