My tenant will be transferring security deposit into my business account.

Chicken and the egg.A non-refundable earnest money deposit, or option purchase, might help you get it under contract.

Once I plan to offer the unit, I offer it contingent on successful background check: In addition to the basic applicant approved transunion smart move through buildium which I pay for, when smart move stopped providing criminal background data, I  added a $49 tenant paid service through rentprep for nationwide criminal and eviction, bank account deposit verification, and employment verification.

Which would also help me recoup some extra to add to their security deposit, since prior landlord only charged 1/2 month rent for security deposit.  

He ask for a $500.00 deposit, which he would return after you completed all the calls.

If I had submitted a non-refundable deposit but the financials still made sense I would still go through the same process.

If you know that something major will need replacement in the future, increase the monthly amount you are depositing into your reserve fund.

Consider all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.

I did receive another few deposits of about $6K dividend. 

The vast majority of lawsuits against Landlords are for wrongful eviction, security deposit disputes, and Fair Housing Violations.