2. Door/windows: It is a rare 12' wall that does not have an
opening of some sort in it. Planning puts all, or almost all, butt
joints above/below the openings

No matter how carefully you tape a butt joint, you will end up with an
unavoidable "bulge" in the wall. While this may or may not be visible to
the eye, it would make the trim installation more difficult if placed over
openings like that.

Anthony