People get crazy about cash flow in house-hacking, as if there's some magical line of good and evil between being $5 in the hole or $5 in the black.

Often what has caused the most damage to a structure is past owners careless remodeling cutting notches holes or completely through structural members of the home.

Or going to down the online rabbit hole of you tube and google. 

I own a rowhouse in Baltimore that I'm renting out and my neighbor's roof has a hole in it - a racoon is going through that hole and into the attic space above my tenants' bedrooms and making noise, which the tenant is complaining about. 

One older guy smoked as the younger dug the hole.

I expect to spackle nail holes and wipe down counters and cabinets to make sure they are "double" clean, but I am local.

That is a big hole.

Hmm... then this goes into another rabbit hole of handling this "lemonade out of lemons" which can also end poorly. 

(Broken windows, heater broken, leaking water pipes, electrical problems, holes in walls, rotting porch, among other damages.)The buyer continues to make payments, but if they stop then you have a ton of repairs before you can rent out the house.

People who invest and also add sweat equity would be partners proportional to their monetary contribution and get paid for the work they do separately.