The site itself is fine. I personally put in fake info. They do not send an email to verify it is correct so as long as you put something in like z@z.com it has all the parts of a "valid" email.

There is usually an opportunity to ask live questions...but don't count on that working. The host will (at least the last couple times) tell you to click on the "raise hand" button, but then he fumbles looking for the name in the long list of participants to allow the person to speak and so NP becomes impatient and says "lets just take the next question". So the submitted questions usually get asked more often.

From the last couple I've been on, they've had maybe one to two live questions at most.