f i'm calling a tgirl and i'd like to know sexuality information such as if she is a bottom, top or versatile  how can i ask without her getting offended or assuming this is solicitation or "vice " questions  ?  

 if i don't ask her and we get started in the session without previous discussion/agreement, then you csan guess how misunderstandings and confusion can happen cause a session to go bad on both sides.  
what is the best way to ask a provider if she's versatile, bottom or top without offending her and getting  
instantly disconnected .. or cussed out .

Read reviews and see how things play out........if she is not a top, typically it is clear in the ad when they say they are a bottom or feminine girl............

I seriously doubt you will ever get anyone offended by asking...........hey, looking for a full hour of fun.....I am a top and bottom....how about you?

I have followed Dog's advice, and it hasn't been a problem.  No one has been offended.  Yet.  I think it is very fair to ask, and shouldn't be a problem.

Always ask! But look to be disappointed.(most of the time) Always an excuse!

They usually mention what they do in the ad. If not you have to be bold and ask.  If  the conversation does not go well, take a pass.

 
 New providers and some visitors won't always have "reviews"  in fact it's likely the newers
 get nervous and defensive about  being addressed those type of questioning.  
 
 and it's not always about my experience, as i think it's important to ask and address questions
 because on a board like this, there could be others failry new to the scene or haven't heard
 the discussion being brought up before. Not just this particular discussion, but in general.  
 oh, and i have been disconnected at one end, for asking..while most have been receptive.