. - I didn't do a BRRRR since it was too difficult from 2000 miles away.

Texas is difficult as a Californian due to the extremely high Texas property tax, coupled by the CA state income tax.

Flips are labor and time intensive but are good for cashflow if done right but can be difficult for new investors without a good mentor.

Honestly the few others that can't be located will make this a difficult one.

The spreadsheet shows the net worth after 30 years is basically a wash between selling and renting it out, so it's difficult to justify keeping it. 

Having roommates can be irritating, but as you said duplexes are more difficult to find in most markets. 

It's closer than fusion and quantum computers but there are still some very difficult technical problems. 

As mentioned, it's a VERY difficult class to insure right now.

However, it might be difficult to discover houses with solid cash flow in high-appreciation areas.

Because Class C & D tenants will statistically cause more damage to a rental than Class A or B tenants.While "maintaining to the neighborhood" is a logical approach, it's often difficult to put into action.