It isn't impossible but as @Jimmy Lieu mentioned, there is a steep learning curve.Depending on your liquidity, out-of-state buy & hold rentals could be your best bet if NYC investing is out of the picture.

I bet you could make little to no money in 20 hours a week.

No, but I looked that up and it is odd how similar it looks to their website, logo, etc.

If you cannot prove income then our rental DSCR loan will be your best bet. 

Then your best bet are probably community banks which have more flexibility (albeit worse terms) than larger banks and also worth looking into are DSCR lenders.

Most people don't sell an STR that is making them a ton of money so odds are it could look better, although they could be selling it for other reasons.

When you have a duplex and tenants on both sides stay for ten years, it almost guarantees that something isn't right.I would study your market and determine the value of your rental, because I bet you are losing money every month.

That seems odd.

Your best bet is to keep liquid cash and avoid PMI.

I feel like I'm drunk as every one is not level or taken at an odd angle.