I assume you've heard the original, 2nd quintet+1 version of "Sanctuary", from early 1968? Davis completely reimagined it (and IMHO, significantly improved it) during the BB sessions.
Re "I Fall in Love too Easily", it's incorporated into the intros of the August 1969 studio version (or rather, versions), not just the live versions.
I view Bitches Brew (the 6 tracks on the original album) vs. the other post-August tracks on the box as being fairly distinct. The latter are certainly very interesting and contain some gems, but the average quality level is lower.