You would have to be very unlucky to end up hooking up with a psycho. I can't say it doesn't happen ever but it's for sure not common. Do a search on this board on how to get verified on date-check and p411, get references and you won't need to give your real info everywhere. Some girls require it at all cost, some don't. It's your call in the end to decide if you're comfortable giving your personal info or not.
I don't know about other providers but I frequently get client's actual information. I don't think blackmail is an objective for most of the providers. We just want to know you are serious and safe. I don't think we are out to cause you any problems, it would certainly never occur to me to cause someone distress...
Most of us are professionals and it would not be any of our best interests to be known as a source of trouble.
And if you keep communications ambiguous, no harm can come to you 
Good luck.
This is obviously not the most likely scenario, but not impossible. Unfortunately, especially for newbies, there are more than a few (ahem) less than stable ladies that lurk these boards from time to time (I do have personal experience with receiving personal violent threats from a provider I never saw). The way it works is the folks who have been around just ignore and side-step the well-known land mines, while the newbie traipses merrily into the mine field.
Most likely, you're fine, and experiencing newbie paranoia as we all did. However, this is what you need to do. BTW, this isn't really that different from a normal appointment decision-making process, when your personal info is requested - which we have all had to do. The equation is all about risk (from being outted) versus risk of drama.
First, evaluate your risk if outted. Are you married or a prominent businessman, politician, etc? What do you have to lose?
Second, look at her reviews and reviewers. Do a search on your local (and the General) boards for those reviewers. Are they active posters with lots of reviews? If so, PM them and ask some polite and discrete questions. Explain what you did here, and ask for their opinion. This is what the advice for well reviewed (and current reviews) is all about for newbies. Ladies with lots of good and recent reviews from well known clients reduces the risk of undue drama (not to mention a bad initial experience).
After evaluating your risk, either book an appointment or don't. If you do, be on your best behavior (clean, on time, donation as requested and no dumb questions about "illegal acts"). The bummer is, if she is psycho, just deciding not to book could be enough for her to get POed.
Here's the tricky part. Deciding about reviewing her. You can skip it altogether if you think there could be drama which could lead to problems for you later. If all goes well, and you want to review her, it's probably OK to mention that you saw her reviews on TER and ask if she would like (or mind) for you to review her. If the session was positive, you're probably OK. If you think you need to write a less than glowing review, again, you have to evaluate the potential for drama.
I cannot stress enough that 95% of the time, everything is cool. However, as with everything iin life, there are some not nice people and there are real risks.
I don't have enough hobby experience to know for sure, but I have plenty of experience being paranoid!
Your post is still missing a lot of info, but here's a question - conditional suggestion. Which telephone number are you and she using, the one on the business card? A separate hobby phone? Which email are you using?
If everything is limited to business card name, b card telephone number, b card email (maybe), I would drop this now and keep her out of your future loop. "How do I know who it is? I give out HUNDREDS of b cards. How am I supposed to know how she got my info or who gave her my b card?" If you have incriminating b card email emails, that argument could be out. And dozens of phone calls on your business card, forget that.
If the sum of your contact info with her can be explained innocently or accidentally ("plausible deniability"), I'd drop trying to see or contact her. In most cases, she'll write you off, too, and leave you alone. In the sub-1% chance that she calls, you have plausible deniability.
If you have good separation of stuff (b card real name, but contact via hobby phone, hobby email), things change.
Good advice. Also keep in mind that some providers want to check the info on your drivers license when they see you for the first time. When that happens they have lots of personal info if they want to mis-use it. This is another reason to, at least at first, see veteran, heavily-reviewed providers. That way you know they are pros who would never mis-use your personal info because it would destroy their business.
