#1 problem with this:
NO ENCRYPTION IS PROTECTING THE PERSONAL DATA WHATSOEVER!
Granted, I'm sure you could still use this plugin over SSL...do you really think all these wordpress users even know how to setup an SSL connection let alone use it? I predict many security issues caused by the users (WP admins) inadvertently allowing the world access to their customer data (even if it is just simply submitted straight to PayPal).
