You wouldn't necessarily be "writing in your layout". You could do something where you have a separate preview pane that updates in real time. Similar to what Apple showed earlier this year with their Swift playground IDE, only for typesetting.
Huh? As a European living in the US, I've had the opposite impression. I've never been to another place where every restaurant will automatically give me a free glass of water (and continuously refills it) without me even asking for it. I've also never gotten a dirty look for sticking with just water.
In Europe, you generally have to pay for bottled water, unless you specifically ask for tap water (and get a dirty look in response).