Just keep promoting and sending lots of targeted traffic and the sales will come! Keep up the good work!
Yes, commissions can be stolen pretty easy if you know the code. To protect your commission, you need special plugin that makes sure you'll always get your commission. I have the plugin (check my sig), but since December 2010 it doesn't work with Clickbank anymore, but it still works with other affiliate programs.
Not sure how that's possible. The only real way for someone to "steal" your commission is by hacking into your host and changing your hoplinks to their own. And in that case it would be pretty easy to find the culprit since you would have their CB account ID.