Q: How do I shut off "face recognition"?

You can't.  Let it do it's initial thing and the ignore it after that.  It might scan new imports but those won't be very large and will be over with quickly.  It's the initial scan that takes a whille the first time an existing library is scanned.

You can send a feature request Apple via http://www.apple.com/feedback/iphoto.html.

OT