I am hoping the seller will be understanding but curious if seller can back out from sale and forfeit my earnest deposit for this 3 day delay? 

Mike, thanks for your response, I am in the process of finding a bank, when you say they have to be verifiable I am assuming you mean bank deposits/statements for the rent rolls from the seller?

The contractor is not paid until job is complete, so you can minimize risk of them taking your deposit and not showing up to work. 

I do plan on taking that portion from her deposit.

I would think they should be able to show paystubs for the year to date earning divided by her hourly wage to establish average amount of hours per week and then see if that corresponds to her W2's for the last 2 years and if they all match up and her debt to income ratio works, move on.  

If you leave the property by the lease expiration date AND leave the property clean and in as good condition as you found it I will not charge rent for Jan. and I will return the security deposit in full" I made the offer contingent on them responding to my message. 

If you can get your deposit back and be made whole, I would definitely walk away from this one.

Think of 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'd also ask for a higher security deposit, but otherwise would probably consider renting to them.

Security deposit needs to be returned minus deductions.