It's those areas that will have lots of cash buyers.That being said, unless you work an area that is really remote, really undesirable or really high end, you are not going have a problem finding cash buyers in this market.

Dont trust anyone or you will end up holding a undesirable property.

Evicted undesirables in one side of the unit and re-rented.    

With respect to the law of building codes, permitting and contractors, I have to be frank--in Ohio, it is nothing more than a hidden tax, a protective tariff, and a way for the municipality to veto any development or renovation that its architectural review board subjectively considers "undesirable."

Some related reading for you, since you seem to not like research (an undesirable attribute in an agent, BTW):http://www.biggerpockets.com/forums/21/topics/170-how-to-find-a-good-realtor-http://www.biggerpockets.com/forums/21/topics/74296-what-defines-a-good-re-agenthttp://www.biggerpockets.com/forums/21/topics/69232-what-do-you-actually-look-for-when-selecting-an-agenthttp://www.biggerpockets.com/forums/311/topics/70483-how-to-find-a-good-re-agenthttp://www.biggerpockets.com/forums/21/topics/69807-value-of-using-an-real-estate-agent-in-the-deal

Many homes that are bought by investors would not qualify for traditional financing anyway, so they would either sit vacant which attracts vandals, druggies, and other undesirables, OR an investor rehabs and resells.

Those 20% are undesirable areas. 

.)- house hacking; there are not likely very many multi-family units in many towns and if there are they are probably expensive and in undesirable/dangerous parts of townI am not trying to discredit the usefulness of this site or of investing in real estate.

Of course he would, he already made me go cordless on my laptop peripherals (Hey, why isn't my mouse working?

Zero regulation now might lead to oversupply with no barriers to entry and then could swiftly change to a super difficult regulatory environment whereby STR becomes undesirable.