Landlord Tenant

Are landlords required to change locks when tenants move out?
My daughter lives in an apartment in Tallahassee. She is a student at FSU. At her apartment there were 4 tenants for a four bedroom 2 bath apartment. Each tenant was on a separate lease and only responsible for their portion of the rent. Two of the tenants transferred to another apartment in the same complex and paid $175.00 to transfer. They came back into my daughters apartment after moving out last week without my daughter being there and used their old key. I called the rental office and told them about it and asked them when they were going to change the locks. The rental office told me they just ask for the keys back and were not required to change the locks. Isn't there a law for when a tenant moves out that the locks are to be changed?
What happens if I break my one-year lease early?
I have a lease for rent of one year. If I want to move after six months, do I violate the lease? What will happen to me?
Did I violate my lease by not fixing my flat tire in time?
I am on a lease that states a flat tire on my vehicle must be fixed within 24 hours. I went out of town on 12-5-06. I arrived back 12-8 06, and my truck had been towed and impounded for a flat tire. Did I violate the lease?
Who is responsible for carpet replacement in a business lease agreement?
In a landlord lease agreement to a business, who is responsible for carpet replacement when it is not defined in lease?
Can a lease signed by my landlord's daughter be used against them in court?
My landlord filed an unlawful detainer action (eviction) against me. She filed a rental agreement as Exhibit 1, stating that I am not in compliance with our agreement; therefore I should be evicted. However, I never saw the agreement before nor did I sign. Her daughter signed it without my knowledge. Could her daughter's signing the agreement be used in court against the daughter and landlord?