Replace the oil heater with electric cadet wall heaters or baseboard heaters.Go with for the 240volt models.

I'm no structural engineer or architect but looking at the drawing, Is it possible to pitch the roof where the high point connects the center of the wall with the fireplace to the other pitched roof? 

Owning a condo can be worse than renting an apartment with bad neighbors because it is not so easy to give a 30-day notice to move out when you your next door neighbor cannot sleep unless he is playing his thumping music that vibrates your walls all night while you are trying to sleep.

The roaches live mostly in the walls and other interstitial space, like the area between a 1st and 2nd floor. 

It would have to be a permanent fixture, tied into / connected to the walls.

I have rebuilt the walls and have coated with redguard (the pink paint), which acts as a waterproof membrane. 

"I think you have mice in the walls, I hear them scratching"...

Hopefully the inspector/contractor can evaluate the issues and costs to fix since these things are behind walls.

It's now at the point where the base cabinets are swollen with water & mold is growing under the kick plate areas & up the bottom parts of the walls.

Let me explain.I bought this house here for 7 cents on the dollar.https://www.zillow.com/homedetails/52-Stonybrook-Rd-Gales-Fe...Feel free to look up the address, see who bought it, and for how much it was purchased.Now, their backs were not against the wall, they owned the house free and clear.