Having said all that "keep it simple" is not good advice, imho. If my ePUB
can and should do X, then Smashwords should not expect me to stop doing X just because Word doesn't support it.
I'm already angry that ePUB supports two different sets of footnotes and Word does not, so all my footnotes were re-worked in the Smashwords version.
And the "break things up by chapter and screw up Ana's chapter heading pictures" is
NOT a Word thing, it's a Crappy-Conversion thing.