What you feel comfortable with should guide you.  There is always a risk that it gets into the wrong hands (LE, etc) and bites you.  Having said that, most of the ladies are just trying to make certain that you aren't some phsycho that's going to harm them.  In general, they don't care about your personal info.  The ones that have called my office have posed as someone that should reasonably be calling (credit card fraud dept, dentists office, etc).  Then again, I only deal with women that have enough reviews to make me feel comfortable giving that stuff to them.

Good luck.

Follow the board in the Twin Cities, discussing just this issue.  We have problems with ladies who keep EXTENSIVE databases on their clients.  Unfortunately, it has come back to bite many, in different ways.  

Verification should be for the ladies to ensure their safety, and nothing more.  Unfortunately, it doesn't always work out that way.  

Only give out what you are comfortable giving.  I do believe you'll find that it won't be an issue, with a reputable gal, but you are never2safe