Barnacle_Bill,
You're spot on there, the way the online test is designed, it would be extremly hard to score 100%.
Without going into specifics, as it is frowned apon, the phone interview is quite basic, not to much to worry about.
From my experiance, it is basicly to confirm you are a real person, and know what you are applying for, plus some situational questions.
No real way to prepare except to read over their (the ASA) website, and be confident while speaking.
Good luck