What tactics would you use with your spouse to get him or her interested in sharing a too-big house with nice people you choose that you may not even see frequently in order to pay a very low monthly net rent and maximize the ROI on your primary residence rehab?

Currently you can find 1000sqft apartments in decent neighborhoods starting at $45k and homes starting at $60k , this is info i found online Bolivia is one of those places where people are still old school and you find the best deals by word of mouth.

People are always fearful.

whereas most people do not respect utilities that they do not have to pay for the utility bill could get expensive in my opinion.

So, keep in mind what a good tenant expects in your area.For example, if you have an existing GAS furnace and central air conditioning already a simple replacement of the gas furnace gets people what is likely to be an economical heat source while also providing a/c which many rentals don't have.

It’s hard to do for paycheck to paycheck people.  

As long as you are approaching people in a respectful way that you feel good about you can't help how people will respond sometimes.

@Pauline Sabado B-ham has seen population decline, but people I know there advise looking outside the city proper.

Go to meetup.com and search real estate for these meetups to link up with people that know your local market and that are doing it! 

There are many homes in areas outside of Claremont that are selling for $500k to $650k Many of the people we know are buying homes like this one with a construction loan for the ADU ($100k) and buying a home for $700k + $100k : $800k total at 5% down payment and ending with a total payment (PITI) of $6k minus $2k rents from ADU Total new payment of $4k which is easier to make and once interest come down some, they will refinance to drop their payment to $3k to $3,500 per month.