I agree that you pull the string with a pull off, because you want the note that you fret behind that to ring out and it doesn’t really do it noticeably if you just lift.
Also fits with what I learned on guitar back in the day. Oh and with Module 16 - Lesson 3. I quote Josh: “I’m actually pulling the string across with my pinky finger.”
Regarding the clacking it seems a ‘local’ problem that doesn’t reach the amp!? Can you hear what you are talking about on the recording?