S.R.
Both of my boys are too young to tell you what I would do for sure, and in my neighbor hood, I often see lots of chidren, some appear pretty young, that walk to school. I think that letting the walk to school is a litle much obviously, but I think that maybe if the kids would be willing to stay in view of your house that I might be willing to let him go out for a little bit. Close enough that you can still see him when looking out the window and far enough for him to feel like a big kid. and make sure he understands stranger danger!
What part of riverview? That is were we live :)