The short answer to the original poster is this: yes, the brothers do not discriminate against illegal immigrants. This is evidenced by the enormous influx of illegals, especially Mexicans, into US congregations 8-10 years ago, during the economic boom. Our area, like many others, jumped at the opportunity to form extra congregations. Spanish speaking congregations were popping up, then splitting, almost monthly it seemed. Many attendees could barely speak English, and the majority were unquestionably in the USA illegally.
WT sent out a letter to the BOE around 2009 or 2010 (I am sure someone has it handy, and can post it or link it). The purpose of the letter was primarily to remind overzealous elder bodies that they could not appoint a man to a position in the congregation, as he was not "exemplary", because he was breaking Caesars laws.!!!!
This letter put many congregations in a pickle, because " legal" elders and servants were a difficult commodity to come by. Many turned a blind eye, and appointed anyway. I saw it firsthand. Many reports were fudged, just enough to sooth the pricking consciouses of the elders, so that they could claim ignorance if some "needed" appointments happened to slip by the great Holy Spirit.
Even more interesting was the fact that ZERO emphasis was put on the fact that these ones claiming to be Jehovahs people were blatantly breaking the law, usually in multiple degrees.
Why, you ask? Why not crack down on the lawbreaking congregants? Easy..they were making good money in the UP economy, and could donate TONS to "mother".
Its easy for WT to pick and choose what laws they care to follow, when its all about the money!