@ MC-FutureCPA
From what I understand, if all you're waiting for is the last section, you don't need to enter any info at all. If you passed the final section, it should give you a message right away that says you passed all parts and can not re-register. If you want to view which sections are greyed out, ie. you haven't taken 3 parts yet, then you would need to fill out the info.
The difference in NASBA vs. non-NASBA is how involved the state wants to get in the score distribution process. Non-NASBA states get the scores from NASBA and then post them directly to their state board website or send the score by snail mail. Maybe it has to do with monitoring, statistics, etc…who knows. And no, I don't think you're paranoid at all. I think it's counterproductive to collect sensitive information to verify your identity in order to grant you access to your insensitive information. I'd rather have my grade leaked than my maiden name, DOB and SSN.