I think it will prove to be especially important as I evaluate possible properties in the future.

One particular point can not be over emphasized; even if someone has and is willing to invest the capital in attempting to build or scale their business or investments, they still May fail if they do not possess or can not evaluate those who CLAIM to possess the necessary expertise required for scaling. 

2.How can I better evaluate and communicate an investor’s return on investment (ROI)?

So, for everyone else who cannot possibly evaluate every deal in detail.

I never go off of a flat percentage on anything, I analyze the costs to get to a specific return I target and analyze the risk that is involved. 70% may be an initial metric to see if it is even worth pursuing, but every deal should be evaluated independently based on costs, time and risk involved.

Evaluating deals on this site will help you understand expenses, income, and financial statement.

If you don't know how to evaluate whether or not it is a viable investment, why would you make an offer?

Are there any particular things to check when evaluating such a deal?

Evaluate forming an LLC to protect both parties and outline everything in an operating agreement.

Learn how to evaluate a market by either reading and listening to a lot of content or by providing some sort of value to someone who already has that knowledge.