No it doesn't errode confidence, most customers are not part of the startup ecosystem. (unless your target demo is other startups) To be frank, I'm not sure what Posterous being acquired by Twitter has anything to do with most of your points.
First of all, Posterous is not bootstrapped, it's received $10M in VC funding. Second Posterous has few customers compared to users, but well paying ones like Coca-Cola, I'm sure they will be taken care of.
If you have a product worth buying your customers will not question how long you've been around. Some will but there are enough that won't. If you're really worried about it, buy an off the shelf company with updated filings, it's not very difficult to find a company 3 or 4 years old. If you've got the cash you could even buy a publicly listed shell. Even NYSE shells come up now and then but those are very pricey.
But honestly, unless you're selling items in the thousands of dollars per month range no one is going to pull your corporate charter.
As an aside, do you offer Cilantro in bulk / whitelabel or do you have an affiliate program?