streamline checkout process

I'm looking to make the following modifications to ProdCart checkout process. Any help would be greatly appreciated, as I'm new to ProdCart and asp (I'm a php guy). The first mod is the trickiest, so I could definitely use some advice.

1. Move the email address field to the "Address" step for customers checking out without an account. Requiring an email address during the first step implies that an account is being setup and may be offputting to some customers.

2. Combine "No, I would like to create one on the next page" and "No, I will checkout without creating an account" into one option. This will make the process clearer for the customer. I also plan to re-word the option as "Checkout without account".

3. Get rid of "Summary" step altogether. My client only accepts Credit Cards and doesn't use Gift Certs, so I hope that removing this step won't be difficult... perhaps a simple redirect that passes along the proper variables for payment method.

4. Allow customer to step back in the checkout process by clicking on steps in the step-by-step image. I plan to create my own individual images for each step of the checkout process and link them to the proper files. Haven't tested this yet, but shouldn't be too difficult.

Thanks for any possible advice/help.

- peter