I only have one problem that is a little bit hard for a person with my level of education and experience to admit.   

.• With recent demand, asking market rent growth is soaring, to its highest level in 20 years at 12.9%.• More than half of San Diego submarkets recorded double-digit rent growth and asking market rents have grown by an average of 17% YOY ($2,600/month).• The current pipeline of 7,300 units will be unlikely to apply much upward pressure on regional vacancy rate.

I am trying to accumulate wealth and decrease my stress levels.

Been there, done that.....Now you can keep the existing ground level garage and install new structure above to carry the new load.

The only commercial level appliance I have is a 36” range, it’s kind of hard to justify having anything else in a regular home.

Are there regulations at the Federal or state (Michigan) level restricting the number of rental occupants per bedroom and siblings per bedroom?

I doubt it is for tax reasons, since IL and NC are not much different at the state level.

This is a classic raised ranch (bi-level), 3x2, at about 1500 sq feet, built-in 1995. 

Also varies greatly on what class of homes you have / they have and the income level. 

The dollar return isn’t everything; as alluded to, the time required to manage the investment and stress level should be taken into account.