Looking over the confirm page I can see why you don't get to the success page. I think that you could get it to work out by setting the server up for testing mode. In the PowerStore Admin go to the settings and for the site check the box for test mode. This should allow it to get to the line of code that sets the redirect.
Once this value is set and the email is sent the next thing thing the page should do is redirect you to the checkout success page. Post back and let us know how it works for you.