I wouldn't rent to someone that is short of my monthly income requirement UNLESS there were sufficient compensating factors that would mitigate my risk (ex. co-signer).

How you are being compensated, and 3.

I would suggest bring up some kind of compensation.

I spoke to him (the son) briefly yesterday as I was at the property for the home inspection - he said that him living there has been part of his "compensation package" from his father for managing his father's properties.

It was up to him to collect rent prior to closing, or raise the price to compensate for that.

Good news is - you don’t pay more for a great lender typically because banks pay a ton for advertising, and great lenders are referral based so they can be competitive, and be compensated well without charging you more.  

Compensation should be based upon those rather than relationships. 

I think it will potentially reduce my total cash flow, but I’ve adjusted my marketing to compensate for the added benefit and disadvantage of having a live in property manager.

I'm considering taking $100 off rent for Nov/Dec/Jan to compensate for the increased electric bills.

Are you offering realtor compensation for bringing tenants?