Sorry I have no help on the tantrums.

On inattentiveness, could it be interest related? I always remember my mistake of signing DS up for baseball when he was 5yo. When it was time for pitching, he was out in the field... either scratching his legs or looking up in the sky. After the game, he asked me "Did you see the clouds? They looked like candy floss!". I should have known he was never into team sports.