You will get more responses if you start a new thread for this topic, so I encourage you to do that.
As for the mealtime issues, try tackling only one lagging skill at a time. Reward when he does well with that one skill. Also, allow him to eat standing up or to sit for 5 minutes and then take a movement break before coming back to the table.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism