#1 IAFD names are based on actual names and AKAs used in movies. Girls often use different names on websites. These names have nothing to do with helping ID performers and credits in movies. The IAFD sometimes will include an AKA from a major website with a major performer, but this is the exception. And, when we do, we notate next to that name where it comes from... (example: "(ALS)" next to an AKA is just such a notation).
#2 If we know the scene pairings, there is a scene listing showing the performers paired together on the movie's page. Not exactly spoonfed as you request, but it is knowable (if we have the scene information).
#3 Jeff?
#4 Jeff? (Personally, I don't see any advantage to the IAFD in facilitating wholesale lifting of database information. The IAFD is a FREE service. And, as with many websites, it is the click-throughs to the advertisers that pay the bills to provide the website in the first place.)
I maintain my own database of every movie/DVD I own.
I check IAFD information against this list before renting/buying, and find this to be quite easy.

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