I am open for any discussion and business proposals. 

One more thing to consider going forward... typically with co-ops the Board has to deep dive on the financials of the proposed buyer (not a foreclosure purchaser, but an end buyer, if the goal was a quick flip).

Drew my set up is identical to what you proposed and I’ve never had an issue.  

How do you know if the proposed seller finance terms are your best option? 

I would offer to propose a lease renewal for a year closer to market rent.

Otherwise, you’ll need to apply for a zone change which is easiest if your proposal is consistent with the city general plan.

If I am to propose this solution or opportunity to a home owner; they are signing my documents, not the other way around.

I know of some RE agents that do what you are proposing ... they trade their services for equity instead of cash commissions ... the difference is that they also throw in property management services into that mix, target high net worth individuals that are out of state and/or don't want to mess with hands-on part of investing, and they build their experience on their own investments first (don't use your investors as a guinea pig ever), they still put some of their own cash into the deal as their investors want to see that they have some "skin in the game", and they do it with multifamily properties (sometimes big commercial property, sometimes 4-plexes).

The emails might be a tad high, but I have no idea if you were asking him to explain to you, in painstaking detail, exactly how the various different tax bill proposals throughout the fall might or might not affect you, if you were asking him to calculate possible 1031 deferrals, preparing a significant tax plan, or whatever.  

Even if it is fairly dented, the solution proposed above would work.