Foreign documents accepted by brokers/owners?

Just Google it!

Here, did some research for you: https://www.hauseit.com/buying-property-in-new-york-city-as-a-foreigner/

For buyers, doesn't seem like there's extra hoops. Be wary of firpta when you sell. For renting, sure same applies as domestic renters.

There are management companies that are good at working with you if you are coming from outside the US and can show a letter if employment (with your salary), visas, and probably make a security payment of 3-6 months. You may also need to have higher minimum salary requirements. My experience is that they took no consideration for anything from outside the US (guarantors, credit history, bank accounts, etc). Glenwood, which has no fee rentals all over the place, seems to be good though picky. Others are a pain - I had one company not accept my bank statements from the largest US bank because the account was registered in Virginia vs New York after I had been in the US for 4 years. There is some discretion left to the individual you are dealing with - some are xenophobic and will ask for all sorts of nonsense. In this market you just move on if it seems unreasonable.