A family of Microsoft word processing software products for creating web, email, and print documents.
The document contains Content Controls. What do you really mean by "the entire app freezes"? Do you have other documents open and it affects them as well? Or, is it just the case that when you protect the document containing the Content Controls, you cannot edit that text that is not contained in the Content Controls?
Maybe you need two versions of the document, one that is unprotected for those who need to be able modify the text anywhere in the document and one in which all of the text and the Content Controls have been "grouped" by using the Group facility in the Controls section of the Developer tab of the ribbon.