Hi everyone,I'm considering purchasing a single family home property in Union City, NJ, and would appreciate your insights on a plan I'm thinking about.

This sounds like a good plan - sticking to the duplex or SFH for students is good too since most DSCR Lenders generally stay away from "student housing" but if you are looking to purchase a rental property that can easily be utilized to rent to any tenant (adult, family etc) including students, you should be OK

The variance will be granted based off the site plan submitted at the time and the variance application.

I've done this myself more than once.You will want an architect (figure a few thousand for plans).

rent by the room, rent by the unit (small MF), rent out an ADU, etc.If you plan on renting by the room, then maybe more square footage and potential rooms to rent.If it is small multi-family, then you can look at similar size rentals to see what their market rates are or use programs like Rentometer.com or BP rental rate calculator. 

My plan involves paying off the first mortgage's judgment amount afterward.

We are planning to turn our primary residence into an STR at the end of this year and are looking to take advantage of accelerated depreciation if we can meet the REPS requirements.

My outstanding loan balance is 163K @ 3.5%I calculated that I'd clear 900/mo after expenses.I was planning to buy my new house for cash, but with the market where I'm moving/buying I'm having to go about 100K over what I was planning, so I'm taking out a 50K loan for that property.

You won't get the replacement cost if you plan to walk away.  

Many resorts hire seasonal staff that needs housing.All said, if you can acquire well, and your plan is appreciation, Tahoe is an awesome place where real estate is a limited resource.Consider snow removal.