Headscratchers / Kamisama Kiss

• If a God's Sacred Wordbinding assures the complete and utter obedience of a Familiar, then how the heck is Tomoe still putting shitake mushrooms into Nanami's food after she repeatedly orders him not to?!

• What was Mizuki doing at Nanami's school prior to his initial meeting with her? What possible reason would he have to go there?