Feel free to quote me on the "informed consent" of the empowerment spell.

I think you're on to something with the underhandedness of Buffy in "Him". I've never been thrilled with that episode, though like all episodes it has some choice moments. I've put it down to not enjoying the humor of humiliation, but it could also be taht it is the least in character of all bespelled Buffy incarnations that she would undermine Dawn that way. Even under the BBB love spell, when she fights with Amy over Xander, it's a head-on confrontation.