But we made about $14000 wholesaling the next door fourplex and we got this one under market (it appraised for $40,000 more than we bought it)But it’s still frustrating that he is throwing a fit and putting holes in the walls.

I would first identify the viability of finding additional rentals in this market that fit your criteria for investment. 

That's all assuming you can get a successful judgement against him.Honestly if he's a creep and not communicating, that may work in your favor. 

I was thinking that they get paid the most when there is turnover, so has anyone been successful in crafting an agreement that rewards for:Tenant longevityShort vacancyKeeping repair costs down (I do want to address issues though)Dunno...

I will check with them and see if they would be a good fit.  

They don't fit every deal or every borrower though. 

I was successful reducing the tax by a couple thousand dollars on one property a few years ago doing it DIY, but my comps for another were bad and got nothing.https://www.state.nj.us/treasury/taxation/pdf/lpt/ptappeal.pdf

@Jordan MoorheadThat's awesome, I work at Anytime Fitness currently. 

I am also a licensed real estate broker with Nottingham Realty Group and I have had a lot of success helping investors (both local and out-of-state) buy investment properties, repair them, and either lease them to quality tenants (BRRRR) or sell them as a flip (BRSR).

If you don't know what a unit will rent for, you have no idea what you can pay for it and cash flow.I'll leave it at that, but stay focused, be willing to spend some time and be patient, and you should be able to have success here.