1) Listen to funneldrill.
2) Only thing I would add is to discuss (or have a coach you trust discuss) the two strike approach. 22 K's in 81 PA's is a lot. Granted, this was a very, very good season for a 10th grader...but you asked about areas for improvement, and this one seems obvious to me. From a strictly sabermetrics point of view, cutting the strikeouts in 1/2 gives him 11 more times of putting the ball in play... say he gets just 2-3 hits out of those 11. Batting average goes up, but more importantly putting the ball in play 11 more times does the things funneldrill talks about, and that is helping the team win (moving runners, potential sac fly, reach on error, etc). Cutting the K/PA down even more will give even more opportunities to improve the stats, above and beyond the natural progression of a hard working player.
Even then, if the majority of the K's are 7+ pitch ABs, then he's working the pitcher and competing against a tough guy on the mound that day. Tough to be critical of those types of ABs. This is where the raw data you posted, while beneficial, doesn't tell the whole story.
Again, congrats on a very good season, and good luck moving forward!