For the tags and relations, I have followed exactly the same pattern used elsewhere within City of Denton and other nearby communities that also have enclaves of unincorporated territory. If this is wrong, then it's wrong everywhere.

Sorry, "badmin" was a typo produced when entering tag values. I've corrected this. As far as admin_level = 8, this is the value used for all other city limit feature for City of Denton, so I didn't change it. Per the wiki page (boundary=administrative#admin_level=*_Country_specific_values) "8" is the correct value to use here. This particular area is an enclave of unincorporated territory surrounded by City of Denton. There are several enclaves and exclaves like this in this part of the city.