and could they change the school?
Yes You may receive a provisional aid offer from a school and then find out that it changes later.
What if I my living expenses are not as high as has been estimated by my school, can I turn down the other loans that has been offered to me?
You are entitled to turn down any loan that is provided or even to request a lower amount of borrowing. Your school will be able to help you with this query, should it arise