Best way to determine values of a property is price per sqft on similar year and style properties and of course that varies per condition but it is the quickest way i found to price things.

But this obviously depends on the lender 

Depending on where you're pcsing to, you may be able to manage the property yourself or at least do a trial run.

The reason for this being that most lenders see travelers as unstable because we change jobs every 13 weeks, our income often varies, and we often have gaps in our employment between contracts to travel, be around family, ect.

It depends on WHY there’s no rentals.

Lead success vary based on markets.   

Depending on the type of "group home" (drug/alcohol rehab, handicapped, mental illness, elderly, etc.) you have other laws to make sure you comply with, and great point by David D Painter re insurance.

You also have the "cost" of your time, which will vary a lot, especially as you ramp up while learning the STR ropes.  

That depends on deal to deal since the condition of each property and requirements of each seller will be different. 

If you have the 80% LTC loan, keep in mind that the lender will likely require anyone with a 20% or more interest (that's going to vary from program to program/lender to lender) to guaranty that loan along with you.