For single family residence I could easily run comps by looking at Zillow and getting a handle on an area, through recent sales and valuations.This becomes much harder when analyzing multifamily since there are fewer comps, and there are other factors to figure out, such as what are the units in one apartment building renting for.This is my biggest obstacle at the moment.

I did an appraisal earlier this year in NE Minneapolis for a sale of a single family home that had a small ADU detached in the backyard.

For an example of a house hack scenario, my last purchase if at 96.5% LTV (3.5% down FHA loan) would have required $15,470 plus closing costs to purchase a detached duplex (3/1/1, 2/1/1) each with their own yard.  

Question #2 - Is there a way to "detach" the lien from the house and have it basically attach to the sellers credit only?

The homes around here are in the 1200-1800 sf range, 2-3 BR, 1-2 bathrooms and some have detached garages, but usually a carport. 

If I were starting out I would start house hacking a detached duplex somewhere that you are willing to live. 

A tagline used on some other forums I visit is "patience and persistence will overcome most obstacles."  

I lucked out last year by finding a single family detached property in Bed-Stuy with a R6A zoning where they're building 6 condos now, which I assigned for a 6 figure paycheck so I have to learn more about what can be built in a given zoning. 

The big obstacle with using the VA is that I have to live in the property for 2 years until I can rent it out.

The highest rents for beach houses tend to be on Sulllivans but they're the most expensive to buy as well with most detached houses out there being over a mil.