Although the 'bones' seem solid, this is an old house that needs a good bit of updating in each unit. 

That plan sounds really solid. 

As of now I have a solid network of laborers each with their own specialty of trades at really good prices, my partner, has been a contractor for over 30 years himself and managed many flipping properties and has a good understand about the industry.

That way the investor is tapping the benefits of cash flow and participating in appreciation over time.Lastly, If we do the math, someone who has a good solid investment portfolio in large markets can now fund several MF investments in smaller markets using a relatively small portion of equity in their existing portfolio.

Pick a solid B-Class suburban area.

This assumes solid middle-class income and a decent amount of equity in a current primary residence. 

I already feel like I have wasted  SO much time by not learning about real estate investing sooner... thank you for the advice, I have some reasearch to do now!

Stock options, great retirement and good pay sounds like a very solid path for the future regardless of real estate investing.

All have been solid thus far.

If nothing comes up for a trusted contractor source then I'd turn to local businesses with a solid reputation and rating among the community.