If you have a w/d spend a few more bucks for stainless-steel hoses and a water monitor/shut-off.

biggest unseen expenses I can anticipate might be floor joists, electrical, plumbing (it's got public sewer and water), and perhaps just general full cosmetic replacement if the tenant moves out.

I said to my banker Heck half of Charleston gets a little water in the street at king tide whats the big deal.. we worked through it. 

I feel that based on my interaction with them, that they would be responsible pet owners, although pets always incur a level of damage.  

Fixing a gas leak on water heater $110.

Not being able to soak an arm or a leg in hot water in my home isn't acceptable.

They also ran some plumbing out from the corners of the home to run all the gutter water out and away from the foundation.

My concern is damage and changes of tenants. 

It's hard for me to imagine pet damage that extensive though.I'm wondering if the smell penetrated into the insulation behind the walls at the lower levels and if it's getting into the new / cleaned areas and "reinfecting" them?

My partner and I are in negotiation for a 6-unit property in NE Ohio, below are details: 4 rented, 2 vacant / average rent $735 (4 rented units $720, 2 vacant $775)Owner pays water, sewer, trash2 br, 1.5 bath, roughly 900 sfGarage with door + extra parking areaRoof in good shape, air and furnace in good shapeRealistic gross all units filled: monthly $4,400 / yearly $53,000We walked through both vacant units, very clean and basic.