Further. With regards to point 2, this (
http://blog.laptopmag.com/epub-prime...now-and-more/2) states that;
"When you first start the program, ADE will scan your computer and add all of the ePUB files it finds. If you load books to your computer later, you can still add them to the library."
..which places some credence on the scanning system to populate its library line of thinking.