I have never been a JW, but when I first started posting here I was paranoid because if I got found out the elders might tip off my JW friend as to what I was up to! So I can imagine it must be much worse for you!!
Basic tips: don't give your real location or age. Be careful about any identifying information. Folks who have been here for a few years, have been to apostafests, or who have decided to give their real information are folks you can feel a bit more comfortable with. Personally, I have met 1 person in real life, and talked to 4-5 posters on the phone (which is not much compared to others!!).
Anyway... I hear ya about being paranoid!
bebu