They vary. In many cases you are not required to put money down until after the bank approves and you actually open escrow. In a highly competitive situation I advised my client to actually deliver the deposit check and open escrow. Not sure how much it helped but the offer was accepted over other offers. In either case it doesn’t matter because you can back out and get your deposit back. I have seen a case or two where some listing agents try to have buyers sign documentation forfeiting some of the deposit if they walk away while approval is being done. I would not advise to sign that.
Anyways no it is not hard to get earnest money back in ANY case as long as you did not remove your contingencies and/or are not past the contingency removal date nor have you signed anything stupid. Your agent should be able to advise you on the do’s and don’ts but in essence you are good to go and in the majority of short sales you don’t submit a deposit. Each transaction is unique though.