I'm not sure how I go about proving he lives there, and as this is my first property (and first tenants) I'm afraid of some sort of retaliation if I "stir the pot" so to speak.

Get a copy of the police report for the OD.Any unathorized people in the unit staying there not on the lease..If so write up lease violation.Get a crime free / drug free addendum for all your renters.Give them a notice of lease violation, High traffic, meaning just that to many people at weird hours.If you smell or someone else smells pot it's a lease violation and write them up.Non-renewal at next renewal time with proper notice.Offer mutual lease termination, or say any further incidents you will file for cause. 

Stuff that hits loop net is the stuff that is passed over generally.

So if took in $3500/mo in rent and maintenance was $691/mo and taxes were $700/mo and the insurance is $900/year so give or take the net is $1900/mo.

My gross is $42,360 and my net is $33,000 cash-on-cash.  

I do feel we made need to sweeten the pot even more for him, but he's not losing anything but Time?

Pots/pans/containers, but all in great condition. 

If this is a small low return deal, you may sweeten the pot by giving a preferred return prior to you the GP receiving any of the cash flow.In the end, it will come down to what seems fair for the both of you to make it a win win.

Well, in the old days, as well as these days, as long as the toilet wasn't blocked, we would instruct the tenant to fill a bucket or a pot with water and dump it into the toilet to flush until the tank fill mechanism was working.

Thanks for the feedback, I certainly have been very fortunate to have the job that I have had and it has made a lot of this possible, its kind of like investing with a net, I was able to take a lot of the risks that I did because in the back of my mind I always knew that no matter what I had a stable income coming in that mitigated a lot of my risk.