Yes, and yes.
The very fact that you asked those questions is evidence that you should rescind until you are more comfortable with your purchase decision. If you wait, you won't have the option to change your mind.
Assuming you rescind, the same deal (or approximately the same deal) will be available at a later date, even though you might have heard some version of a "today only" speech. However, I'm betting that you'll make a much better decision than to keep or sign up again for this deal.
You'll get a lot of advice here suggesting that you take your time, read what's on this site and eventually buy resale rather than from the developer. It's all good advice!