Thanks for this. I'm sure it's not quite as scary as it sounds, but the only thing I can think of that's more challenging than "start a business" is "start a business in a new country where you don't know the language." The "friendship treaty" seems like a great idea, but right now I'm not a very good friend.
I have friends who've moved to the NL via DAFT. You'd probably do well to hire an accountant who can deal with the tax authorities (who are the only branch of gov't that will not speak English to you), but the business doesn't necessarily need to cater only to Dutch speakers.
And while it's nice to learn the language and all, the NL has among the highest English competency in Europe. It's rather difficult to learn Dutch because English is so useful and prevalent.