My Checkout Without Account Mod

[KGZotU]

I've come up with a checkout without account mod that I'd like to get some feedback on. It seems pretty solid, I developed it on one store, then packaged it and installed it on another. I've put it through its paces, and as far as I can tell it does everything I want to perfectly.

I'm putting it out as a beta, and am looking for the community's views on language, phrasing, usability, bugs, proper practices, etc.

I've got links in my sig which link to the mod and a demo store. Feel free to perform whatever experiments you'd like there.

The Pithy Explanation:
This mod allows users to checkout with or without an account. Like all other such mods it creates an invisible account which requires less effort/commitment from the customer. However, my mod uses a particularly simple method to keep the problem of multiple accounts with the same e-mail address from effecting those who create permanent accounts.

I've pasted this further explanation from the readme:

What this mod does:
When a visitor adds something to their cart and proceeds to checkout, they are greeted with three options. They can sign in to their existing account, they can create a new account, or they can proceed through checkout without an account. They are only given this third option if they have something in their cart. After entering their billing information they are sent to checkout_shipping. If they somehow manage to enter the COWOA sequence without something in their cart, then after they enter their billing information they are directed to their empty cart.

A visitor may COWOA as many times as they like using the same e-mail address. They may COWOA using a given e-mail address, and then later use that same e-mail address in the creation of a regular account. They may not COWOA using an e-mail address that is associated with a regular account.

There's more information about how it works in the readme.

Awaiting feedback,
Joe