Within a week of him moving in, we had numerous complaints from neighbors and the HOA about loud noises like domestic abuse, etc.

Great motivation to live lean, invest in real estate and reap the rewards!

There are numerous models to follow.  

I have NO desire to waste anyone's time ( including my own ) but like many other owners receive numerous inquiries and if the day does come to sell in the next year or two what would be an advisable screening/interviewing process.Thanks in advance for any thoughts on the topic!

Usually yes but when a loan changes hands numerous times oftentimes these things get lost in the shuffle. 

Teddy R Lease Option Assignments has risk, sure, but if you do them well you can mitigate/manage the risk.As Jon Holdman has alluded to the risks, there are rewards if you do the following....1) pick a 3 or 4 bedroom house in a good area that people want, good school district. 2) find a home seller with little equity that can't sell.

I personally don't have the "grapes" to invest out of my area because the risk exceeds the reward.

This has been a very rewarding experience and I'll save 5K per month.

I am not sure a reward at the end of the year will do the trick, I am seriously considering a monthly cleaning service provided as a perk with each rental for $30- $40 a month I will have some insurance that the property is well maintained and it will act as an informal inspection.

Every time I purchase or refi a property, I state numerous times very clearly that I have a mailing address (PO Box) that I want everything sent to since I do not live at the subject property and don't want my mail going there.