You can't beat the price, either, or the interest rate on deposits.

Now, I'm imaging a scenario when every one of these tenants move out that I'll be paying their entire security deposit + interest even if there are damages beyond normal wear and tear. 

This one I might take from the deposit, depends on how much if it is really worth it.

This method is simple, free, and fast.You could also provide deposit slips, so tenants can deliver their payment directly to the bank.

The money is deposited in the 1st even, if it’s a Sunday or a holiday, it can’t bounce, and it can’t be taken back. . 

A realtor who used to have a PM company called "JBS Realty" until this month.He used to manage 8 of my properties and is currently refusing to pay out multiple 5-figures worth of rents/property reserves/security deposits/unpaid utility bills owed. 

Quote from @Aj Green: Quote from @Gregory Wilson: The real issue is how much of a deposit do you have to try to get back from them.Sure, your contingency might work but I assume you gave the deposit to the seller.

Additionally, bank statement loans could be an option if you stay in service and deposit your tips consistently.

This is exactly why you take a security deposit.

Expenses have exceeded the security deposit, plus many hours of work by me.