This ensures you have a clear picture of what repairs are needed and helps avoid surprises during the rehab.

He missed significant repairs that turned a $10,000 refresh into a $60,000, 8 month rehab.

This is my first time reading of your experience with this property were you able to complete the 80K in repairs ?  

This will reduce your risk and cash invested and if something goes wrong you wont be bled dry with never ending repairs.

Single family house, which required smaller down-payment and little cosmetic repairs.

I'd call insurance before having any sort of plumber to come do any repairs.

I find that cash flow is very important so that I don’t have to come “out of pocket” to pay for major improvements / repairs  

Expenses incurred before the property is in service are considered capital expenditures and must be added to the property’s basis rather than deducted immediately.This means costs like rehab expenses, repairs, and other improvements made before the property is ready to rent are added to the property’s purchase price and can be depreciated over time once the property is in service.

Quote from @Dan Grove: Some combination of cash to seller, closing costs, repairs, construction, paying off arrears, assignment fees, commissions.   

Told me the violation wasn't corrected in the 30 days required timeframe (yes you are correct, the repairs were done in time but they didn't come out to confirm).