Second, I was concerned that they would move out and take the oven/water softener/light fixtures etc. with them and say 'those weren't part of the deal'.

For example, if I can run water/sewer and electricity out there, insulate the walls, add some windows, drywall, finishes, and appliances for $30k-$50k, that's less than any unit you could buy anywhere in Portland.  

Some of the issues brought to our attention by current tenant would need to be addressed by the seller before acquisition.There is a potential piping issue or cracked pipe somewhere as the tenant complained about some water level problems.  

Your roof (or water heater if you will:)) will cost the same, so that $20,000.00 property with a $600 rent all of a sudden looks like a pretty crappy deal compared to a 200,000.00 property with a $4500 rent even though the percentages is way higher.

It's amazing how much one can save on the water bill alone just by replacing the toilets with a new water saving one, which can cost as low as $30 from the big box stores.

On physical inspection all of the electrical panel had been stolen, all the wires cut out of the attic, water heater, and air conditioner as well. 

I just renovated the bathroom because it was terribly outdated with cracked tiles and water leaking into the basement and I am planning on re-building the porch because it is a potential safety hazard.  

I provide information forms to all new renters giving them the pertinents - location of water/gas/electric shut off, phone numbers to all utilities and emergencies, trash & brush collection info, specific information about maintaining/cleaning the house, etc. 2.

I do know that there have been stricter rules and guidelines regarding water runoff and such since much of our ground water eventually impacts the Chesapeake Bay. 

Your utilities number looks low - $200/month for cable, wifi, heat, electric, water???