With your proposed seller finance terms, you'd see serious negative cash flow for years! 

I proposed to put down 20% (50/50) on a house where we can live together and invest the rest on other properties since she said she does not want to live in a house that is only mine...I won't ask why.

Now, the Feds are proposing another program that will directly inject billions into the economy.Why?

Could you please cite the source of this proposed legislation?

The solution that was initially proposed was that friend/business partner would have his 25% equity split bought out of the funds that the 3 equity/capital partners are bringing to close and then he would take 25% of the backend profits.

But that conclusion is more about what is convenient for the CPA rather than the client they are serving...Unless the losses can be tracked without filing the state return and then captured as suspended losses when there is passive income from the syndication (this is what the OP’s CPA is proposing to do) - how is this possible? 

The buyer has proposed 13% downpayment, 4% interest, interest only payments for 3 years and then interest only plus $1000 for another three years and then loan paid in full. 

For extra formality, put it on a nice document with your letterhead.Re: Non-Binding Letter of Intent to Purchase Real Property Located at [Property Address]Dear [Recipient's Name]:This non-binding Letter of Intent ("LOI") is submitted by [Your Name] (the "Buyer") to [Recipient's Name] (the "Seller") with the intention of setting forth certain preliminary terms and conditions for the proposed acquisition of the real property located at [Property Address], inclusive of all improvements, appurtenances, and fixtures thereon (the "Property").Purchase PriceThe Buyer hereby proposes to purchase the Property for a total consideration of $[Amount] (the "Purchase Price"), which shall be subject to adjustment based on the results of the due diligence investigations and final negotiations.Earnest Money DepositContingent upon the execution of a definitive Purchase and Sale Agreement (the "PSA"), the Buyer shall deposit earnest money in the amount of $[Amount] (the "Earnest Money") into an escrow account designated by the mutual agreement of the parties.

I wanted to propose he sell to me at a 20% discount and I would lease it back to him for an extended period of time. 

I would pay Wealthability if I see that the proposal would indeed save us more than we pay for the fee.