This appraisal came in at 130k , this is not beneficial to the deal.

Any ideas on how I can structure this loan at a fair-beneficial offering for all parties and/or pay it back?

I had a inheritance and placed most of it in Mutual funds.

There are only a few circumstances where a cash offer is more beneficial to a seller.

Would taking Real Estate classes or even acquiring a license be beneficial for an aspiring real estate investor?

I have total faith if you put in the work and implement the correct systems – you will see where it can be very beneficial. 

It would be very beneficial to bounce ideas off a real estate minded cpa, any references would be great!!

-adjustable rate mortgages/loans do pose a risk should the rates move-hloc are beneficial since you can move money in and out, and since they are interest only it helps your dti ratio-you could mitigate the interest rate hike by simply refinancing when you see the rates rising. 

He can get primary interest rates and a lower down payment by living in the house, which would be really beneficial to your ROI.

My concern is that if I do this with one tenant, if another tenant wants to leave before lease term end and I don't allow it, will it be deemed as favoritism, or as long as I have a formal documentation of mutual agreement there are no issues?