I saved a copy of the Word document and deleted all but a few pages to serve as a sample. I then turned off track changes, accepted all changes, and also inspected the document and removed custom XML data and watermarks and identifying information.

The interesting thing is that now the paragraphs appear to be completely formattable, just as I needed them to be. My next step is to go through this process again, see which step fixed the problem, and determine whether I can apply that step to the original whole document (for instance, accepting all changes is not a workable solution - my client needs me to track changes). I'll do this and report back.