is it ok to use words like gfe in emails?

To be honest, no one gets arrested for typing anything, its getting caught in the act the causes problems.  I suppose hypothetically that if caught and facing trial an ad with too many specifics could be used against the defendent.  There was a story in a different post about a disclaimer in an ad being used against an agency...so anything is possible.

I would think that, short of "give me money and we'll have sex", any verbiage in an ad is fairly inocuous!

but you have to take your cue from the provider.  If she says on her website no discussion of activites, then take that to heart and do not do so or she may cut you off cleanly and you won't see her again.

The less reference you make to any activites, the better.  If she has reviews, then take those to heart as to what to expect at your session.

Not for me lol. Overwhelmingly for most ladies I'd say no.