@hitch: Yeah, lke I said, not really fussed about white boxes on the chapter head and the odd decorative image. (Yes, I saw the comment about Harry Potter - that's a great go-to to tell customers that have problems!)

"shaded" - customer wanted a light tan background colour in alternate table rows. Looks lovely... well, if only they didn't want fancy glyphs for icons in one of the columns which I then had to conver to images for fear of embedded fonts not being reliable.

Interesting though that the converted image background inherits the table cell's background colour from the first instance seen. Surprised that they've gone to the effort of being that 'clever'.
Does the Kindle support transparent GIF?
Pfft... why would they ever do something as useful as that?
Eh, embedded fonts have been pretty reliable for a while, if the glyphs are supported with unicode. If not, of course, if they are out-there swashes and all that, that's another thing altogether and it's a bugger if only a given font has them--then you have big-time issues when the user changes fonts.

On the shading--well...that's doable. Tables are always rough, the choice between the smooth and the not-so. We still use our typical 3-4-columns, not-more-than-10-15 rows "rule of thumb" in deciding which way to go.

Yes, having the HPs does help with fractious customers. At least something does.

Hitch
Hmmm.. I thought I saw a thread recently (dont ask me which) where someone said that you can't rely on embedded fonts. Might have been an iOS thing? I've not had problems embedding fonts in the past.

Hilariously: All but ONE of the icons are found in a font that I embedded, but one of them had to be taken from a different font and wouldn't render. Would have gotten away with it ALL if it hadn't been for that one pesky glyph!

Oh, the shaded table rows work just peachy on KP3 not a problem AT ALL.
HANG ON HANG ON HANG ON..... I think I've found an alternate glyph that I can use in place of the toublesome one the customer was using. KP3 likes it. If Only I can convince tham that this one is so much better than the one they used. They can have their striped tables back

... though I'm not gonna get the day spent on this back though. Ah well, c'est la vie!
I would make sure that you test on things other than KP3, just to be on the safe side. KP3 is...it's almost a browser-renderer. Don't get me wrong, it can be very reliable in lots of ways, but you will get performance and alignment and other things in KP3 that you don't get in the wild.

And of course, make sure you test in KP2.9x, too, in the DX emulation, for the KF7s still loose out there.

Hitch
The problem is that Mobi will not work with embedded fonts. So if you are relaying on font(s), then you are screwed.
Jon:

And what "mobi" file are you talking about? The KF8 mobi most certainly will, but she can never upload it now, b/c a reflowable MOBI can't intake any longer.

So it's moot. She can upload an FXL MOBI or an ePUB (or zipped HTML, etc.)

Not sure why you're even mentioning MOBI and embedded fonts, really. The older (KF8 aka "dual" thanks to Calibre) MOBI-style files are being created from the uploaded ePUBs, for distro to the older devices (DX, etc.).

Hitch
You could also create zebra striping with pseudo selectors not listed in the Kindle Publishing Guidelines.
For an example, see the screenshot of a KF8 book taken with my old Paperwhite 2. The epub2 source file is here.