Great idea for a post! http://saastr.com/ is a great source for startups in the SaaS space, but more so for growing in general than specifically addressing your point.
Though, I think you summarize it pretty well. Straightforward and honest answers to address objections.
Yeah, I love SaaStr and read it regularly! And I'd love to see a SaaStr post on directly addressing customer objections about buying from startups, for startups trying to sell to cautious SMBs and especially enterprise.
I've certainly rolled this concern right into my own startup. It is more or less a monitoring tool, and provided as SaaS, so if the startup should go out of business for some reason, the customers would no longer have service, but they'd no longer be paying for it either - they'd be no worse off than they were before they started using my product.
Though, I think you summarize it pretty well. Straightforward and honest answers to address objections.