First Template is different from document.
Templates in Microsoft Word
Templates are something to use in creating documents, not something normally sent elsewhere.

Second, don't have a clue what Header/Footer Tools have to do with protecting a document.

Third, yes. Use the Developer Tab and restrict editing. Make the areas you want others to be able to edit "Exceptions." This assumes they will be using Word 2007 or later.

Note, you can also enable Track changes, put the document in Final view mode, and lock that before you send it to them. That way, when you get it back, you can very easily see what was changed, and perhaps by whom. This is under the Review Tab.