Is the best approach Jason to build everything, functionality wise, with the wizard, test it, and THEN build our page layout (header, footer, nav etc) around it?
What would be very helpful is if the Wizard only overwrote the cart sections as opposed to the entire page. For example, if you run through the Checkout Wizard and get everything set up with your pages and THEN you realise that you've mapped one of the fields incorrectly, for example, then you'd have to go back into the Wizard to change it, or hand code it I guess (which removes the point of having the wizard does it not?)
If we toggle the Sandbox on and off, we have to replace the real credentials with the Sandbox credentials, right? Or will the Wizard remember the real credentials? I don't see an option to add both anyway.