I think I will just have to keep my fingers crossed and hope that they stay with me until my closing date. So as for their deposit and considering the circumstances do you think it's fair of me to require 2 weeks notice from them so I can apply their deposit to those two weeks?
But if your contract says they have to give you 4 weeks notice then that falls within the two week deposit so you will have them pay for the first two weeks of the notice and then they can use the deposit for the last two weeks.