Another issue is the gas station includes a liquor store so opening a new company to buy out business would mean losing the age of liquor license which may be beneficial in the future if they pass a law on permitting more liquor licenses to existing holders. 

You have positioned yourself exceptionally well at your age, you don't want to mess that up by jumping too quickly.

The tenant segment we've targeted for over 17 years is families with elementary school-age children and a gross household income between $65,000 and $85,000.The only properties this segment will rent are:Type: Single-familyConfiguration: 3+ bedrooms, 2+ baths, 2+ car garages, 1,100 to 2,400 SF, one or two stories, lot size 3,000 SF to 6,000 SF.Rent range: $1,800/Mo to $2,300/MoLocation: See the map below for the areas where our target tenant segment chooses to live.What has been our results following this process?

"limited access to capital until retirement age" - I don't like this statement.

Make sure you know the EXACT age of the roof from the seller and if not, you might have a problem even getting the house insured for roofs older than 15 years old in some states5.

It comes down to niching down to the target audience (ie 30+ years ownership, built 1980s and earlier, owner age 70+).

Then I read in your profile, 500 units by age 24?

Today is an age the USA has long not seen, COMPETITION.

They did this while they continued to work in plumbing and dry cleaning until they retired at age 62.

Age group 4 and up.