For context, we are stable income-wise, so no concerns about a job loss or injury preventing us from making payments.

A very simple but big concern that arises is an exit strategy - what if you purchase the property over market value, and suddenly need to get out.

honestly, its not clear what you want vs. what you are "concerned will happen..." 

That's it in a really small nutshell...There are lots of concerns/pitfalls/issues with wholesaling. 

Even when my secured Financing is single Closing with construction to Perm Loan, interest rate @3.125.The concern is around the contract with builder.

Even when my secured Financing is single Closing with construction to Perm Loan, interest rate @3.125.The concern is around the contract with builder.

I will be debt free and well "ahead" of the curve per my age bracket so far as net worth is concerned.

Another concern I didn't mention here is that I've already done pre-auths with 3 different lenders (a couple 'preferred' lenders with new developments and an independent), and I don't want to get too many hits on my credit.

I’m just concerned that the profit is going to be eaten up by taxes.

@Elliot ColeSome of the best tradesmen aren't licensed contractors, for roofing I would not be overly concerned.