As a smart investor one should not get caught up in the buyer frenzy and stick to their principles of smart investing.  

I need some advice because there may be ethical & "bleeding heart" flaws in my plan.  

If you read books and take course to learn how to run a successful remodeling or construction company, they are often the exact opposite principles of what I read in blogs on this site and others about hiring a contractor.  

I would structure this as a 30 year loan at 3% interest + principle with all the proper arms length paperwork.  

While we still want to live by this principle, we feel that paying all cash for all of our rental units will simply take too long.  

Or should I take advantage of my current monthly payment and pay extra towards the principle which can help me pay off the property sooner.Thanks!

If in ten years time you are not where you want to be as a real estate investor, if you haven't achieved your goal of not needing a job, if your properties are barely generating any cash flow, if you seem to be acquiring more properties and less equity in them, it will be because you spent your time on "motivational" education and searching for the elusive "technique" that will lead to riches, rather than acquiring a genuine real estate education, one that includes the theory of property ownership, real estate finance, real estate law, property management and investment principles.  

The Reit or whatever investment vehicle that part does not matter as the principle is the same regardless.

Option to pay towards principle after minimum monthly payment is met. 

Your professional education requires effort and a maturity level beyond the level of college students attending frat parties or youthful happy go lucky work ethics.