I am no longer style-supervised, proof-read or edited. When I was, I found things like forced Oxford commas, international spellings, capitalised nouns and passive-voice irritating. Now I determine my own style and have long used minimal open-punctuation.
An email goes:
Dear Person
This is what I want.
Further content, punctuated properly. Sentences as short as possible.
Yours, Brick
Contact details
A letter on paper is the same, with a subject line in bold, handwritten signature and extra paragraph spacing if there's room. It should fit on one side.
In an article or report, only headings, captions and perhaps lists would be unpunctuated, but that's always been the case in my experience. I always punctuate content fully, though I'm no expert. Even in comments or text messages.
I don't mind unjustified paras (like here) if the line spacing is clear and consistent. I think justified with single line space is worse for clarity. Line spacing is as important as any other punctuation. It can be varied between different elements, as long as it's absolutely consistent. Definitely not random. And nobody needs two spaces after a full stop. Nobody.
Edit: I put two spaces before that last 'nobody' for effect, and it was autocorrected to one!