Hi, I was out of the apartment one day after the lease end. So that lease ended 10/20, i had all my stuff out 10/21. I didn't ask for a "month-to-month", I also did not choose to extend the lease. The "month-to-month" i was billed for charges for November and December.You lived there - of course they can charge you rent.
As for the walls, you have a good case.
On the $350 for the wall. The lawyer is $200/hr and they will only advise. It's not worth it. I will like i said call again and let them explain to me how the walls are my responsibility.