I'll be contracting all the work out myself

Hopped up on the adrenaline of their first wholesaling seminar, they are sure they will have 100 deals in the hopper this weekend, but don't have money or an idea on how to structure a contract.

How should the contract be handled moving forward?

I suggest you write up a contract with your seller and take it and your GFD to a local title agent. 

Originally under contract with a wholesaler, I resolved complex development issues, including acquiring and recombining an adjacent parcel, to meet zoning requirements under the city's new UDO laws.

Originally under contract with a wholesaler, I resolved complex development issues, including acquiring and recombining an adjacent parcel, to meet zoning requirements under the city's new UDO laws.

However, there was no formal agreement or contract between us regarding the ownership or any financial details related to the property.

Is there a clause in the contract that ties you to him after the 7 days?

Thank you Flipping a contract, GET to a local RE meeting, 

And since there's no mortgage you might be able to find a modest rental close to you that will provide a positive return.It sounds like you are already under contract to sell your investment property.