House before 1970 have cast iron drain and wood frame house are more accessible to termine and foundation problem.   

How ironic, I’m converting a residential property into commercial.

I find it so ironic that the majority of us are experiencing varying degrees of this good tenant fortunes, yet many are posting of "Housing Market Collapse" and speaking of how doom is happening, the end is near, blah blah blah.

I gut everything including the knob and tube wiring and the old cast iron plumbing even if it is still in good shape.

There is also a dent in the dishwasher and a curling iron burn on the sink.. are these all things the tenants should be charged for?

Hard for any of us to say if it's a good deal, since we don't know the area....it is a 1937 house though so beware...Main things to look for: 1) Roof 2) Foundation 3) Sewer (Cast Iron?) 

Are drains PVC or old cast iron?

Make sure you iron out all details of the deal.

I recommend starting with your first rental/house hack to iron out the process, and develop your system/team.

It's only been a couple months, so I am hoping to have all the kinks ironed out and to be running in a way that we can replicate/modify with the next property.