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. 

- Can you can wait out the expected rate decrease next year and don't want to flow the rental?

Make sure you understand you markets, if the market were to take a 10-15% decrease there is a good change you will lose everything you have worked for.  

Just like any type of real estate it is very risky but your risk decreases as your knowledge increases.