Any marriage, when its legal in that place/country it happened, is considered legal in US (assuming its not like under-age or bigamy or illegal stuff). When a U

Any marriage, when its legal in that place/country it happened, is considered legal in US (assuming its not like under-age or bigamy or illegal stuff). When a US resident marries (& even if foreign spouse has never set a foot on US soil), IRS does allow only Married filing together or married filing separately, in both cases if no social of spouse available, you write NSA (No Social Account Number) in tax return. People adjust (or gain) status all the time while they are here already in US on some other visa. Having a temporary visa is has no good or bad effect on getting green card. Its similar (easy or difficult) in other countries as it is in US, its not "easy" in other country(ies) to fake address if it is not easy in USA. Pregnancy (removed from all facts, sole pregnancy) is never on its own a proof of bonafide relationship. Who is the bio father? The whole collection of proofs when seen as collective, tells the picture & intent. USCIS & agencies has to follow a manual & policies & procedure (much of it is published on USCIS's website), & 99% of the time the officer can not intentionally bring a personal bias (exceptions apply). There are millions of cases getting passed, & a single USCIS employee does not decide a single case. Like any other big organisation, everybody is doing apart of process. & they have managers, & managers above them. Even USCIS itself is not above law, people routinely sue USCIS in federal courts to challenge their decisions (or lack of decisions).