I will pay off his tax debt and we list it for sale lower than market value for a quick flip, it will have room for my desired profit and he will be able to recover 30-40k of equity (vs losing everything)What would you recommend for the contract / agreement / arrangement to protect myself from paying off the debt and being able to list it right away.

I showed up to this arranged meeting wearing a suit, and I'm glad I did because they were wearing custom $2K suits in this low lit bar.  

But most non-private (i.e. hard money, conventional loans) won't allow this arrangement.  

Some arrangements off the top of my head: An option to buy sometime between 18 weeks and a couple years (or whenever).  

I can arrange that by family loans.

I bought a portfolio of properties in March, one of which was improved with a single family home and a 1970SF storage building that resembled a duplex from the exterior but a garage in the interior.

Depending on your level of commitment and partnership and what you mean by JV in this case, I'd definitely be careful with anyone you just met and long term arrangements.

You as the Grantor (owner) of the trust are still in charge, and can easily do this arrangement by yourself.

Agreed with @Matthew Paul - I think your options to make the situation work better than it currently is working are:Negotiate with the seller to get a credit that offsets the value of repairs, although you almost certainly won't be able to get a credit for "nice to have" repairsPartner with someone to take on the initial $35k project costs and give them a slice of the cashflows (or whatever arrangement is mutually fair)Evaluate the cash on cash ROI if you hold on any non-essential improvements up front, and perhaps make them 5/10/15 years down the road.

How to divide my time and arrange things effici­ently?