We don't see bankruptcy as quite inevitable as you do :) In all seriousness, as written somewhere else on this thread:
"We will need to eventually give custodial ownership to a larger entity (think big bank) in the medium term to mitigate the risk of our company going under for the homeowner, such that, if the worst-case scenario happened to our company, the homeowner continues to make rental income as usual."
Startups take a lot of risks, its in their nature, so bankruptcy is always a possibility. Maybe you have the best intentions, but you're not a big bank yet, and even those have gone bankrupt.
Question to the founder: Do you see profitability in building or rental or both?
It would be leaving money on the table for the home owner to continue on the contract for 30years. Initially with 0 equity, the owner gets 50% of rent. at year 20, with 50% equity, the owner gets 50% of rent and at year 25 with say 70% equity, the owner still gets 50% rent. From home owners point of view, it is better to buy out sooner rather than later. It is also not hard to get home equity loans. Thanks and all the best