Anyway, I cant imagine why they would want to stay in my building if they are making so little, but they are refusing to move their equipment. 

I'll reach out to you via email.

I also Cc'd / emailed that letter to the housing authority contact person who handles complaints about section 8 properties. 

Now imagine if you were part of a *COMMUNITY* of investors that go out of their way to help one another? 

That being said, it's very common for listing agents to not respond to emails, texts and phone calls from buyer's agents with interested buyers- you'd never know if they are doing this or not, but I'll tell you it happens all of the time. 

If you are in an FHA loan and you want to buy another home using FHA you would need to refinance before getting another FHA loan regardless.If you have any questions feel free to send me an email I enjoy helping and offering loopholes.

I would start by calling/emailing the different condo/townhouse associations.

I would also say that markets like Manhattan are not super representative of most markets in the US - a lot of foreign investment I'd imagine in NYC, Miami etc - I'd guess a lot of these cash purchases are more about exchanging unstable or risky foreign assets/currencies for perceived stability/safety of US top metro residential real estateI think in a lot of other markets where this isn't relevant - I think most are cash offers being "king" as not having appraisal or other contingencies that might sabotage the sale after 30 days or so and make people re-list (sellers will take less to avoid this risk and downside)

Upon phone messaging or emailing them my first big surprise was that quite a few commercial agents wouldn’t even return the call or seemed standoffish.

Definitely start by documenting everything—emails, city notices, all of it.