Sublet Security Deposit Agreement (sublease, apartment, lease)

[ic97]

I'm going to be relocating out of DC and as a result, I am trying to sublet my studio apartment for six months. For financial reasons, it's quite important that I find a subletter who can commit to staying for almost six months (otherwise I would rather break my lease and pay a penalty). I am trying to figure out what I can do to (legally via sublease contract with approval of landlord) minimize my risk of a subletter leaving before the lease is finished.

First: My landlord did not ask me for a security deposit, only a non-refundable move-in fee. Given this, am I allowed to ask a subletter for a security deposit?

For the subletter, there is a move-in fee as well as an application fee that goes to my landlord of $X, which I intend to pay for. My intended rent for the subletter is $Y. Assuming I am allowed to ask for a security deposit from the subletter, I intend to ask for one month worth of security deposit. Here are a couple scenarios that hopefully someone can answer in regards to the security deposit issue.

a) Is it legal for the sublease contract to state that the $Y security deposit will be returned only if the subletter stays for the duration of the lease (and of course as long as the apartment is returned in good condition)? If legal, is this recommended or will this discourage too many potential subletters?

b) Instead, is it legal for the contract to state that I will return $Y - $X = $Z in security deposit if they give 30 day notice that they are leaving before lease is complete. This way, even though they weren't able to complete the lease duration, I don't lose out on the $X move-in fee and application fee.