I moved here a decade ago and have been in the real estate market since so I can share data that can help you make a safe and informed investment decision.

There are lockable thermostats for commercial use, but I can't see that working in a rental.I think the main issue will always be that any thermostat that you can set a minimum temperature in will always be susceptible to this fail safe failing, due to the possibility the tenant could change it on purpose or on accident.I'd hope in a 4 plex as long as there is no building defect to the thermal envelope that it would be difficult for one units pipes to freeze as long as the other units were occupied, seeing as they share some common walls/ceilings.

Less people go there which means most people there are vagrants or homeless, which makes it feel (and actually be) less safe which makes the neighborhood decline even further. 

The $80,000 would make you $4000 a year just sitting in the bank while you wait for the market to settle - that return is 100% safe and guaranteed with no tenant issues or repair expenses.  

Where are some safe neighborhoods well-suited for house hacking? 

In general, that's the first time I meet the inspector at the property (I won't ask for information before he sees the house...that would be ridiculous).I think it's safe to say that the same approach with an appraiser holds as well.

Rental demand in Orlando is still high and as long as Florida remains in demand, you should be fine as long as you provide a safe, reasonable home in an area that has a need for it. 

So lots of experience both good and bad.from my point of view seller carry back IE seller owns the property free and clear and wish's to owner finance.. this can be pretty safe in some states high risk in others.. whats the difference the difference is foreclosure time lines.

Is it safe to assume the property is still non warrantable?

The only exception was health and safely.