Recapture fights user registration spam by placing a reCAPTCHA on the user registration form.
Sure. Just activate and configure that plugin first, Recapture second.
Are you still getting user registration spam? If so, please let me know. If not, failed attempts at the reCAPTCHA are logged to the Recapture Configuration page, so check there.
Sure, the address is ben c masters at gmail dot com. Though I would much rather hear about specific problems you have encountered while using Recapture, and some possible suggestions for improvement.