Then you can check AirDNA.co (or similar site). 

Cleaning up our work area, I remembered what my old co-worker once told me on the construction site "There are 3 ways a job gets done: One way in our head, another way planned out, and how the job actually goes." 

Here is a video that runs down the basics - https://s-media.nyc.gov/agencies/specialenforcement/01-Legal...There is also a prohibited building list - https://www.nyc.gov/site/specialenforcement/registration-law...Here are some more info overall - https://www.nyc.gov/site/specialenforcement/registration-law..All of this makes STRs in the city pretty tough but it certainly not impossible.

I found them on sunbiz site when I searched  the company name under fictitious name! 

Would any of you recommend a certain site that specifically handles formation of LLC for rental property?  

You can find owners' names and mailing addresses on the county assessors site.

Either way it would be a grey area, selling a house with a different amount of units/bedroom/bathroom seems extreme though. its an auction site, I have seen auction sites miss the fact there was additional lots in a sale.

Check on sites like BiggerPockets, Meetup, and Eventbrite. 

Before buying or renting in an unfamiliar neighborhood, you should check the following two sites: SpotCrime, AreaVibes,These sites provide valuable information, including Livability Scores, which cover aspects such as crime rates, employment, health, housing, schools, shopping, and more.well, anything can happen anywhere.

Vacation rental owners should be on all four listing sites.