Once you start up POL the first time, POL should give you a simple interface to create a SE account, and if any POL account is also required, that interface should automatically create it and link it to SE without you ever seeing it happen. You should be able get right into the game (or at least patching process) within 10 minutes of finishing the install process, after supplying just a username, password and email address.
Account management could still be done via the web interface, I guess. First time users shouldn't need to mess around with content IDs after signing up. A content ID should be automatically created by the signup process, and all the user should need to do is supply credit card (or other payment methods) information.
The POL login screen should have a button that would send you to a (web based, perhaps) password reset function, where you could easily reset your password by supplying for example one of the product keys you used to create the account, and have it sent to you on your earlier selected e-mail.