@David Yee, some advise for decreasing that building costs of the ADU:-Decrease the sqft. 

@Taylor L.Hi Taylor, Thanks for the tip I'm connected with some commercial real estate investors but I guess that I'll need to expand my networking.But still, since the market is very competitive and I know that most if these commercial real estate brokers who has access to these deals will put in a priority their clients that they've been working with in the past, which it's still possible, but decreasing my chances to get notified vefore everyone else.

Long story short, this woman (bad neighbor-happened to be an attorney) wrote a letter of complaint to the building and planning dept claiming my adorable tiny house was blocking a nonexistent view of the ocean (beach views are not possible due to flat neighborhood), "decreased the enjoyment" of her use of her property and (my favorite) was interfering with the air circulation in her home, etc, etc.

Your expenses are going to be basically fixed, and the only way rents are (probably) going to decrease in the greater NYC area is due to a lot of new supply, or some big economic event/natural catastrophe/terrorism etc. that makes living in or around NYC suddenly undesirable.

But in a few years these rates will decrease and house prices will increase.

Your equity is shrinking as these cap rates rise and the cash flow will decrease as well for those that have to refi!

But I might be concerned with the increasing supply of MTRs and decreasing demand for MTRs with fewer travel nursing contracts, and fewer nurses willing to travel for the reduced pay. 

So many new investors get "sold" that real estate investing will decrease their w-2 income as part of the "tax benefits." 

At first, I wanted to go the househack route, but I'm wondering what I'm really gaining from doing this that I couldn't gain from getting a single family, such as renting after I leave to fha another property and live there + gaining equity, besides decreasing my effective mortgage.Also, I imagine in a few years as interest rates decrease, the demand for buying single family would go up and demand for multifamily/renting would go down, or atleast not increase.

On buyer agency agreement it defines exactly what buyer is paying there agent, in retainer, $ paid, and/or %, anything and everything spelled out including if it's decreased by seller compensation for buyer broker.