>>there is also "osake" which is the respectful title, used mostly by women, and which never means nihonshu (as far as i know)<<

'O-sake' is indeed an honorific form and generally in Japan women speak more politely than men and use honorific forms more often, so I agree with you that women tend to use this word. However, I've heard it used by women (and maybe men as well, I can't remember) to mean nihonshu.

Maybe the word is used less in this meaning in Sendai as there are more varieties of alcohol available in the big city?

Like I said, you should go to Festival. The question will be 'nani o nomu? Uisuki? O-sake? Biru?' (What are you drinking? Whisky? Sake? Beer?)
... and that's at 9:30 in the morning....