As a happy leaseback owner of four years, I say do your research and if the numbers work out then go for it. Just leave yourself some sort of margin or exit stratigy in the event things go south. Some other things you haven't mentioned are the tax write off of the plane/business, cost for setting up and maintaining an LLC (which are minimal), money you bring to the plane outside of the flight schools like doing BFRs etc or even your own students. If you are just doing students in the plane and not renting it out then you or a DME should always be in the plane with the student so you can watch over how it is treated. It is a big step but nothing ventured nothing gained. I have often wondered if you could pick up an older turbo prop twin and make any sort of money doing training. For the price of a new piston single you could ALMOST have an older but still reliable KA. I am nowhere near that point though, just a thought.

You may also be able to get the insurance under one of your partner schools umbrella policy, but I have no idea on that one.