What can my landlord charge for

We live in Arizona and moved in October 2020. Our lease is up at the end of this month and we asked for an extra couple days because of a family emergency. The landlord said we can stay until the 4th but only if we get the house move in ready and spotless by then. If it's not ready for the next tenants on the 4th he will charge us for the entire month's rent. Is he allowed to do this? Even if we clean everything perfectly he could say it's not move in ready because he has to do his own maintenance on the property which he would have to do anyways even if we moved out on the 30th. So is he allowed to do that? Also when we moved in the house was not painted. It's just flat chalky walls that chip and you can not wash them without scraping all the chalk off. There are a few datk dirt marks because we cant wash them off without stripping the walls of whatever kind of material they put on it. So is it our responsibility to pay for the painting of the walls when they weren't painted in the first place and if they were painted then there would be no damage caused by us at all?