W/O/W,
3)Shabbos; Do something to get his attention. Ask him what his favorite dish is. Even something not on a usual Shabbos menu. Sushi/McNuggets/Chinese. If all fails, make/buy him a cheesecake for next to his cereal. (If you want to really blow him over, set a place for him for his milk and cereal, and leave a smiley note) Pack him a lunch! (Check with your rov re helping him carry outside) Why do I say this, because any connection is healthy.
4) When he leaves at night, there is no reason you cant say; Please be safe; I need you.
Hatzllocha to you and to “imaofthree”.