Best wishes for your family, but the boy is seven years old. Let him have a childhood.
"...and hopefully one wherein the guts are a bit exposed so that he can learn how a computer works "
Again, he's seven. C'mon, dad, lighten up. The 'guts' of a computer challenge the brains of intelligent people with college degrees. Ever try to explain to an elementary school teacher how a computer works? How to use electrical switches to represent numbers, or how to use numbers to make colors on a video screen? They have college degrees and still have great difficulty with 'simple' computer concepts. Again, your child's seven years old, so lighten up.
"...still keep him interested and without leaving him behind in school...."
Young children have no reason to be interested in computers. So if he appears to be not interested, lighten up, he's seven. Go the the zoo, to the park, or to the library.
With his dad pushing advanced computer technology into his child-like head, there's no way that anything going to be leaving him behind in school.
Again, children are not miniature supermen, they're children. Lighten up dad.