I got several agents referred by friends, and found some along the way on BiggerPockets.

You have to refer to the purchase and sale agreement.

These are referred to as Portfolio or Commercial loans.

I had never met him in person before, just went off references and pictures of his prior work.

I should have known when he kept referring to me as a "friend" but also called me "boss" within the same breath. 2.

If you're referring to commission and closing costs at sale in the future, that is a one time cost that would not be included in your ongoing cash flow analysis. 

Obviously the previous seller was happy with his experience in working with us because he referred us to a friend of his.

Refer fee?

I'm not opposed to S8, however I would want to ensure the tenant still meets my criteria.I agree, credit scores do not tell the entire story and an established employment history with a good employer reference usually does the trick. 

@Lucas MillerYou are using two different terms but referring to the same plan.