I wouldn't mind a toggle on Shirk either, but all of these comparisons to other abilities are off-base.

Rescue literally stops everything you're doing, takes control of your character and displaces you. In a game that's all about strict rotations and positioning that's probably the most annoying, intrusive thing one player can do to another. It's not to say other abilities can't be obnoxious when used poorly, or with poor intentions, but Rescue really is in a class of it's own. It's an entirely different beast.

I want a toggle because it really is THAT annoying to be yanked out of what you're doing and placed somewhere else in a game like this. If people feel the same way about Shirk then it's certainly a discussion worth having.