Agree with your points. Hangar should not be an issue. Working on that now. I figured that the $50/hour maintenance reserve should cover incidentals. I also think the monthly 'subscription' fee would help build an 'incidental' reserve. I have not yet consulted a lawyer as this is in its infancy.
To your point about 'double dipping' think of it less like me leasing to the school and more like me being an independent company that provides twin training and 'partners' with area flight schools to funnel students to me. The positive is that they don't have to own their own twin and they also can provide a whole new set of ratings without farming themselves out to the competition in the area that has a twin and charges $300/hour plus instructor. This way they get a cut (difference between hobbs & tach) and they only have to pay me $35 of the 45-50/hour dual rate they normally charge and keep the rest.