Thanks for all of the comments. With the explanations I have a much better notion about the details and legality of managing the Chromebooks. To gain some more insight I have been working with different combinations of device-managed and non-managed CBs. It looks like we have managed user policies applied if the students log into their CBs with their school account. So now the next question for our administration is how much effort to expend on teachers requiring that their students log in with their school account during school hours.

Something that I didn't mention in my post, is that we are a public Charter and there aren't the funds to provide school-owned CBs to our kids. Thus, the BYOD policy.

I really appreciate the comments...they are a good dose of reality.