Geary at Larkin--safe enough?

Looks like a lot of us are planning trips to San
Francisco this summer. We're going in mid-July.
Would love any suggestions from locals re interesting,
moderate, ethnic food. Especially "real" Chinatown
places (where the Chinese people eat, not those fancy
joints with white tablecloths); Thai, Vietnamese,
Mexican.

Another question: We have reservations at the DaysInn
Downtown-Theatre District location, at Geary and
Larkin. I see from my map that that's in or close to
the Tenderloin District. Anyone know whether this
location would be someplace where we'd feel
uncomfortable walking around at night?

Thanks--

Chris in Long Island, NY (who is finally succeeding in
actually dragging my husband someplace!)