I collect a security deposit hold against the guest's credit card, so that I do not have to rely solely upon the Airbnb "damage coverage".

How much do you charge for a security deposit?

To your case specifically, it would collect both your rent, and your utilities,  and deposit the money into your checking account.  

One lesser-known tool I’ve seen investors use is EMD financing — basically a short-term advance on the earnest money deposit.

Dear Beneficiary,I wish to inform you that your compensation and settlement funds/payment total sum of $8.5 million dollars has been deposited in this bank by the United Nations and the Africa's Fund settlement Committee (AFSC), we have been instructed to release this funds to you as soon as possible and after our meeting today we have agreed to pay you via online bank transfer by opening an offshore account in your name in this bank, after that we will credit your total funds into your offshore account and send the login details to you.Get back to us as soon as possible for the offshore account opening form.Kind RegardsMr.

I suspect that full security deposit forfeiture for lease violation may not be legal.  

Double check the 'proof' of income, not only with employer verification, but with bank statements/deposits.3. 

The seller refused to transfer the deposit.  

Quote from @Maya Jones: You should get something agreed upon for the tenants living and the remaining rent/security deposit if there is something changing from the existing lease. 

To offset the $3100, we were able to collect about $700 from the security deposit.