Pro Sites Checkout Page Redirects to Homepage

I am attempting to setup the Pro Sites plugin. I changed the rebrand field to "Upgrade" and saved the settings, then visited but it redirected me to the home page. I clicked the "Edit Checkout Page" link and it took me to a portfolio page on my site that has nothing to do with Pro Sites. I also tried trashing and saving the Pro Site settings again to regenerate it but it chose another random page from my site unrelated to Pro Sites.

So I have some questions:

1. Why am I unable to get the Pro Site checkout page to come up?
2. Can the checkout be embedded as part of the sign up page?
3. Can I use Gravity Forms Signup plugin with Pro Sites as part of the sign up process?

WordPress 3.9.1
Anti-Splog 2.1.2 (with random sign up page enabled)