I was wondering what an average percentage would be for a down payment of a single family home?

One accounting mistake, one payment going to a personal account accidentally, one use of a personal credit card and poof, you’re personally liable.

I offered $6,000 (after all back payments and fees) and he accepted. 

If your rent doubles you monthly P&I payment, than that property will have no impact on your mortgage application.

Except some counties have been turned over completely to a software company which confused me because they give the request for public info to them and they ask for payment from 300 to 1000.

Yearly rent is 72K and paying 28K payment (include taxes and ins.) plus 7200 in management fees.

Instead of looking at the "equity" (which only makes sense if the market continues to rise and doesn't drop) look at the fees/monthly payments and how comfortable you are with paying that amount (even if wholesaling business slows or your house is suddenly no longer worth the mortgage you have on it). 

And they are basically telling me tough cookies.I want to speak with a lawyer regarding this to see about having them help in the payment here.

The smaller commercial lenders I've talked have asked that I have 6 months of mortgage payments per property to act as a "buffer" prior to lending on a second one. 

If it's non owner occupied you'd need to do a conventional loan which comes with a 25% down payment.