hi garry,
there is one thing, that i would wish being slightly more prominent: aligning to the baseline.
in my eyes it's one of the things that makes a difference for the people coming from office (even if it seems that microsoft office now supports them, too)
currently it's mentioned in a warning at the beginning, which i fear will be overseen by most reader that would need the hint.
personally, i would mention it, when introducing the columns... maybe with a screenshot showing what it looks like.
on the other side, one of the big plus of your tutorial is that it's short, so adding everybody's wishes might be dangerous :-)