You can save the PlayOnline password so you don't have to enter it every time. They switched to a new login system in 2009, with the SquareEnix ID, and they switched account management from PlayOnline Viewer to the web site last year. The instructions with the game haven't been updated much yet, it's been covered in news posts on their site, the forums, and the POL Viewer.

Essentially, most of the problems are from the changeover and account management system being new.