Currently out of need myself (wife and two kids), parents, and two of my special needs brothers are doing a light remodel to the house (mostly due to age or poor construction).

On the first, I pulled comps utilizing similar sq ftg, age, neighborhood, and bed/bath count and the appraiser told me he couldn't utilize those because they are different floor plans.

He takes it and lives to age 96.

2) Given my age (47), goals (cash-flow for retirement; longer-term wealth), and the fact that financing would have to be non-traditional (while I have access to a bit of cash, we are entrepreneurs whose tax returns do not look good in the most recent few years), is considering multi-family my best option? 

Landlords have costs that continue to rise (inflation and age of property).Buying should really only be considered if it's an upgrade.

I made it to the level of Director, with a team of 10 by the age of 28 and I rarely worked more than 45 hours a week - probably averaged below 40 (9-5:30 with an hour for lunch). 

Given that the investor paid $25,000 total for this house with repairs, an owner finance price of $39,900 is fair market value for a property of that size, age, and condition in that zip to someone with no credit history (our typical buyer). 

The carpet is showing its age and looks dirty and stained throughout.

Most policies do cover damage to the roof regardless of age.  

It has nothing to do with actual returns because it doesn’t take in to account insurance or property tax rates, building age or condition, maintenance costs, HOA fees, any utilities, etc etc etc.