Yes.
Unless there is some kind of discrimination or retaliation (enough to convince a judge), this is not permissible.
Yes. No two apartments are exactly the same, so a landlord can charge whatever someone is willing to pay, which may be different for different units.
Your answer depends on what you want to do.If the rent is paid for the full term of the lease agreement, then the landlord cannot rent the unit until the rent runs out.The landlord may want access to the unit to confirm that everything in the unit remains undamaged.If the landlord wants to rent the unit just because it's vacant, the landlord should refund the 'unused' rent to the departed tenant.
Once you have moved out of your rental unit, as symbolized by the return of the key, you are no longer allowed in that unit. Even if you have a duplicate key, you are returning the unit to the landlord by virtue of the fact that you are handing that landlord such key or number of keys you were issued. This allows the landlord to rent out the unit or to prepare it for rent. Therefore burglary charges can be filed against you if you are found trying to reenter the unit.
Was that supposed to be in English?
Theoretically a landlord can raise the rent to as high as he likes. If it's above fair market rent he will have trouble renting out for that high. If he raises the rent just to push you out of the unit he could be taken to court for discrimination.
Read your lease and learn more about how you are required -- or not -- to permit entry to the unit that you rent. Generally, adequate notice -- two or three days -- is required by the association to enter a unit; your landlord may have a different requirement. This is a discussion-worthy point between you and your landlord.
Your rent cannot be raised during the term of your lease. If you're applying for tenancy and the rent is raised, then the unit is being offered at that rate. You can accept it as such, perhaps negotiate with the landlord to lower the rent to which you will sign the lease, or refuse to sign and cancel your tenancy offer.
If there was a lease, the landlord has an obligation to try to rent the unit after the tenant leaves. If he is unsuccessful, the tenant owes for each month that the unit is vacant, through the end of the lease.
Generally, the landlord should not be getting rent from two tenants at the same time for the same unit.
Landlord has to take you to court to get you out and then it will take 30 days before you have to be out.
part of it until the unit is re-rented. THE LL may not, however, keep rent from two tenant's for the same period of time.
No. Your last month's rent is that: your last month's rent. The landlord must allow you to stay in your apartment for the last month and not use that money for any other reason. If the landlord collected a security deposit then he can use it to repair his unit: IF you are the one who damaged it outside the realm of normal wear and tear. He cannot use your security deposit as your last month's rent unless you agree to it.