Lots of missing details that make what was actually going on difficult to understand. Just a few points, as I understand them:
- You do not have to be a US citizen to legally buy firearms from an FFL. Federal courts have ruled as such.
- You do not have to have a state-issued ID to legally buy firearms from an FFL.
- Your address on your state-issued ID does not have to be current for you to legally buy firearms from an FFL.
Now, for all of the above you *do* have to have proof of residency and must be in the US legally.
Beyond that, if the FFL wasn't following current law and ATF guidance then they were putting their license at risk so I sincerely doubt they were not following current law and ATF guidance.