I have a long Word 2010 document which has been protected to limit users to a range of selected styles only. However, I wish users to be able to insert page and section breaks but this feature is disabled with the protection turned on.

In a protected document, you can't insert section breaks unless you first turn off the protection. If users need to do this, you can create a macro that temporarily unprotects the document, inserts the break, and then reapplies protection.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional

The point, however, is that unless YOU do the break (section or page) as part of the macro, unprotecting things to allow the user to place the break also allows them to do other things as they wish.