@Juan Castro Go buy a tube of caulk and fill it in yourself, this isn't a job you should hire out.

And I saw knob and tube wiring as well. 

To help responders you should illuminate the type of plumbing, if the electric is knob-and-tube, etc.

Knob and tube wiring, old plumbing, beat up plaster walls.

It sounds like the possibility of getting the property goes down the tubes when either of these bankruptcies are filed. 

We buffed the floors (rented the buffer at Home Depot and got a buffing 101 lesson on You Tube), painted the walls, got new socket plates, new appliances (fridge, dryer, washer).

I have to say my greatest source of knowledge has come from You Tube only because the information found there is often relayed in a manner I can understand.

With a first walk through I'm more concerned with risks than benefits of adding rooms/baths, etc, because I'm looking for buy and holds not short term flips.Biggies (for me, other people will have different lists): foundation issues, roof issues (look at the roof itself and any signs of water damage on ceilings and walls), mold (beyond a little where things need fixing), leaks in showers that are hard to get at, squishy subfloors around toilets and tubs, termites, knob-and-tube wiring, ungrounded, two-prong outlets, no central HVAC (this is all about your location, some places this is fine), and to a lesser extent water heaters.Heavy duty foundation or mold issues I would pass up, the rest I would consider in my offer price. 

I have watched a bunch of you tube, I have listen to the note queen.

I might add high high likelihood that a fuse panel house is also a knob and tube house.