A lot of buzzing on the bass strings, which he felt could be addressed either by higher tension strings, raising the action, or playing more laterally. Make sure the 16th note sections are very even. Again, record yourself, listen to get the tempo down, to get the feel of the piece. The vibrato seemed too fast, uncontrolled. Vibrato should be varied for the piece.
Many guitarists only have one vibrato speed.
He told an antecdote about his father being made to play the clarinet twice as loudly as he usually did for a week. Use moderate tension at the start of the slide, then let up. Sliding on the basses causes squeaks. Play the rasgueados on high section with all thumb. Don't get off the two-finger chords too soon.