If I understand the situation correctly, the property is not in foreclosure yet, but the owner is behind and you fear that foreclosure is coming. You are also on a month to month lease with the son as your new landlord. He has refused recent rent payments which means the month to month arrangement is now in jeopardy, if not already terminated. The good news about that is you are free to go, which it sounds like you're preparing to do.
Banks normally (buy not always) file foreclosure...
Landlords in Chicago are required to "maintain windows, exterior doors or basement hatchways in sound condition and repair and substantially tight and to provide locks or security devices as required by the municipal code, including deadlatch locks, deadbolt locks, sash or ventilation locks, and front door windows or peepholes;" (CRLTO 5-12-110).
I recommend consulting an attorney to discuss this issue in more detail, specifically whether or not the locks and security you have currently...
In condominiums where the owner has outstanding association fees, Illinois law permits them to get a judgment for the amount due and an order of possession so they can rent out the unit to recover what is owed to them. They are not allowed to profit after that point, but can continue to collect the customary monthly fees from the renter for the upkeep of the building.
If your unit is covered by the CRLTO (city of Chicago) or the Security Deposit Act (Illinois) the landlord has 30 days to advise you of any damages and provide receipts for repairs, then 45 days to return the money. These deadlines are from the date of move out. You may bring suit to recover after that point. If neither of the statutes apply you can bring a contract suit to recover the money within 10 years as described above.
Unfortunately the extreme cold we are experiencing doesn't change the heat ordinance in the City of Chicago. If you cannot afford to insulate the property you must find another way to bring the temperature of your rental units up to code.
The municipal code fines are daily fines and I know from experience the City doesn't take heat violations lightly. An attorney who knows the city code can help you negotiate down the fines and come into compliance to avoid future fines. If you can't...
As to your first question, the landlord can speak to anyone you authorize him to speak to.
As to your second question, since this is a commercial lease, the duties of the parties are largely governed by the contract. Does your lease agreement clearly state who is responsible for the repairs? If it's not clear you may benefit from seeing an attorney to have the agreement reviewed in more detail and discuss options.
If you owned the property at the time of the violation you are still responsible for the fines. If the bank owned the home at the time of the violations, you can go to the hearing and bring proof of the change in ownership and date. This should release you from responsibility.