How many hours/year are you planning on? That resets all the math. Will the 3-5 schools guarantee a certain # of hours?
Have you paid to hangar/park it? what about taxes? Paint, Interior, and avionics should be accounted for as well.
What about the 1K Attitude indicator that slowly dies, or worse - a cylinder or whole motor. How will that be paid for? Does the 100 hour excuse the annual?
I owned a Mooney for 9 years - I can send you an Excel spreadsheet that might help - PM me an email address.
Has a lawyer looked at any "agreements"? Is this your only source of income?