People share bits of their company internals all the time, and often in such a way they that is so vague and general that they don't really violate any NDAs. Your NDA likely isn't that strict anyway.

See: https://news.ycombinator.com/item?id=49353915

Disclaimer: not a lawyer

Not necessarily. It's quite common for friends of friends to spread half-truth rumors.

Frankly yes. Do it in a way that doesn’t violate outright or cover your tracks. Customers deserve to know the truth of the type of company they are dealing with.