The main thing to ask yourself here is the loan officer too slow to respond, or do you have unrealistic expectations?

Very unrealistic.

The issue we are having is the property doesn't "legally" cash flow enough to qualify for DSCR, and, for seller finance, they have unrealistic terms.

I don't think it's too unrealistic in the SD market to rent a room for around 1,000 dollars given the shortage of real estate and knowing as a service member myself that the military pays out 1,900 a month for housing allowance.

Some brokers or agents will give a super high unrealistic number to get listings.

I’d managed the properties myself, and the prospect of trying to do that while living out of state seemed unrealistic. 

(Make sure you are including your closing costs on purchase and sale to compute.)  5% vacancy is probably unrealistically low unless there are long-term tenants (which often means the rents are below-market).

Right now the only thing in the 0-60k range in all of Nassau County on MLS is a house boat in port washington:) You can find some beat up properties in suffolk or some unrealistic short sales on MLS.

For 99% of us this is very unrealistic.

Am I being unrealistic here in my expectations?