I could understand variance with even +/- 10%, but 22% seems malicious to me.My agent said I can either bow out and try to fight for my earnest deposit or try to lobby for a reassessment but some internet research tells me that sellers usually tell buyers to f-- off.

Tenant(s) in place, rents being collected, and in many cases the support team is available OR a Property Manager runs the whole operations and the investor is passively collecting deposits to their account.Turnkey purchasing leads to a B&H investment. 

I had her start escrow and sign my assignment for $18,000 and deposit a $1,000 nonrefundable earnest deposit that would revert to me after 30 days if she couldn’t perform.I assumed Paulette was keeping up the payments and was shocked when she calls to tell me that she owes a lot more than she thought and she had to cancel our deal and was just going to give it back to the lender.

And, while we're having this talk, why are you asking ME to come up with your meagre 5% deposit for your primary?

I'd keep it simple, Application denied.Your going to have to make this type of decision on each applicant.Do you have a set criteria for your rentals.. credit score number, income = like 3 times the rent, verifiable rental history,, should show deposit returned , no lease infractions... if deposit wasn't returned what was reason, was lease term completed..  

Yes, it's kind of a shot in the dark but if they pay your deposit and don't pop on any of your other checks then run with it.

Earnest money deposits vary by location.

I'm pretty old-school in my methods (still get actual checks, not direct deposits) and I'm starting to see the need to move into this decade.

How do most property management companies handle security deposits?

Use a phone app and deposit the check.