A family of Microsoft word processing software products for creating web, email, and print documents.
Unless you're using formfields, there's probably no reason you couldn't use the "No Changes (read only)" editing restrictions for the whole document, with exceptions marked as required - and you'd only need the content controls for non-text inputs (e.g. dropdowns, date selections).
If you are using formfields (which would require "filling in forms" protection), you shouldn't also be using content controls; the two weren't designed to be used together and doing so can cause inconsistent behaviour.