Of course my concern is if the new owner defaults, am I in for a very unpleasant and expensive ordeal to get my money?

We know there might be slight risk of an unwanted visitor, but its' never happend.

Don't be caught with your nailers empty and lots of unwanted inventory.An example in Phoenix; I bought a 5 bed 3 bath for $151,000 and put in $20,000 and sold for $289,900 without a realtor.

These were our first PM and we didn't know yet to negotiate, and what an unpleasant surprise that it took a couple of months to see our first partial payment. 

I bought in a suburb of Atlanta, GA.The Numbers (all annualized):Paid Cash: $77,400Rehab: $21,000 ( estimate was $16k, but when we turned the power on after closing, the HVAC unit was dead).Closing, commission, legal and other: 10,000All in: $108,400Current comps: $115,000Rent: $13,140 Management: $1051.20Insurance: $700 HOA: $150 Property tax: $1,527 NOI: $9,711.8Cap rate: 8.4%The HVAC unit cost 5 grand and was an unpleasant surprise.

Before I'd go forward I'd get real contractor numbers for the rehab, you could be unpleasantly surprised.Also I'd check with zoning for violations, rental inspection, and whether 8 units are legal.

EASY to find great unwanted property for under $1k and double your profit in days.

Otherwise your early leave could lead to unpleasant consequences. 

Another scenario I don't want is one or two adults chaperoning a cadre of teens or pre-teens, which is a definite possibility in summer.I don't see how I can reliably screen out such unwanted scenarios with instant booking.

My job as an investor would be to persuade  ( Don't know if this is the right term to use) the property owner to take less because of their situation (foreclosure, property damaged/outdated, unwanted inheritance, etc.)