In terms of "proof", I can't imagine what you'd accept as proof that I'd want to post here. In terms of risk, benign is a pretty good word for it, and we've been using another processor for years and years without any issues on that front.
I think Stripe is well within their rights to do all the due diligence they feel they need to do; I just wish they had done it before we signed a contract and started taking payments, and it does feel like we dodged a bullet by not agreeing to the Minimum Fee Commitment.