[fomine3]

There's more usage of vertically written Japanese than you listed. Some signboards, some formal letters, many paperbooks (and ebook version), vast majority of non-technical magazines are still vertically written.

Fortunately, for forms, I haven't seen any vertically written forms except school work.

[dfee]

When drafting a formal letter, does the author write it horizontally and present it vertically? Or, is the author expected to have skill at writing a 90 degree rotated character? Or, is the character not rotated, but just written in columns not rows?

[amenhotep]

> Or, is the character not rotated, but just written in columns not rows?

This one. Think about it - they don't expect the reader to tilt his head 90 degrees to read it :)

[dfee]

Formality is often tied to skill. Writing at a 90 degree angle would require more skill, the ability more rare.

Calligraphy, for example, conveys no extra information but is of higher stature.