I get what you are asking. Microsoft never asked you which fonts you need, so they just gave you a selection of fonts that will likely cover most folks uses, including common foreign language fonts.
If you only use one font, you can certainly make a word template set for only that one font.
That would then mean that you would seldom, if ever, need to navigate the font menu.
If you STILL want to clean out all fonts, what happens if you suddenly have a need to create your instructions in a different language?
Or, you need to reproduce a document from another source - which uses a font that does not exist on your Mac?
Try to be open to other possibilities in life.
Anyway, you COULD empty out the /Library/Fonts/Microsoft folder, keeping only those fonts that you know are the ONLY fonts that you will ever use.
Do this after you Quit Microsoft Word, and any other Microsoft apps.
Copy those fonts to an external drive (good use for a USB flash drive!), then drag those unneeded fonts to the trash, then empty the trash.
Dump the font cache file from YOUR user folder/Library/Application Support/Microsoft/Office/Preferences/Office 2011. Look for the file named Office Font Cache, and drag that to the trash.
If you don't see that list of folders, and you DO see folders like "MAU2.0" or "Communicator", then you are in the wrong Library folder. Look again by going to the Go menu in the Finder. While that menu is displayed, press and hold your Option key, Choose the the Library the appears when you press your Option key. That Library folder will lead you to the font cache file that you want to remove.
After dragging that cache file to your trash, empty the trash. The next time you launch Word, it will rebuild the font cache file used by your Microsoft apps.