I have been seeing a legitimate massage therapist for a couple years and she is hinting that she would like to offer more than just massage. Because of the length of the professional association,  and her knowledge of my personal life, I am feeling a little uncomfortable with the prospect of play for pay.  
 Does any one have some hints to make this succeed ,or should I just walk away.

If you've been confiding your detail in her and you now turn this illegal, you'll be the first person she reaches for if something goes wrong in her new business venture!  The appeal of having "leverage" in a man's life is something that few women can resist prying on when they find themselves in a situation that they don't have the resources to get out of it themselves...  With all the pussy on the market these days at bargin-basement prices, i can't see why you'd need to go to the one place you're most vulnerable to satisfy that need, other than to "satisfy" a long-standing lust that you've harbored for this woman which may be the very reason you've been a client to the same massage-therapist for so long in the first place...

You are uncomfortable with her knowledge of her personal life and that is not going to change.

then she owns you! She can make you do what ever she wants you to do (because she has all your info). Also she might feel hurt if you break it off.. The problem with us men is that we (I) want to fuck every woman I get to know. I start to fantasize about them and realize I could get in a lot of trouble. So I just do not play with them.

Did her hinting about more also include additional cost for the play?

She has offered topless for more $. I think I will let caution and good sense prevail on this one. Thanks guys.