I like your recording! As for the tape marking, and just for an idea to you, I usually stick a little white dot (2mm diam., cut out from sticky white paper tape with a hole puncher) on the top side of fretboard at the 7th position (facing you) and stick a little piece of transparent tape over it. It can be done neatly. The tape stays on for a long time, it doesn't take a lot of work and the fretboard stays intact. Plus you can remove the dot if you don't need or like it any more. BTW the sticky gunk can be removed from your fretboard with a little piece of rug moistened with clean naphta (benzine).