Would you want to find “adoberama” or “badobe” ?
Or are you just looking for Adobe as a word? If so, put a word boundary code before and after it (you can find the word boundary code in the @ fly-out menu to the right of the grep field)

There are many ways to do figure numbering, including:
https://creativepro.com/figure-numbering-in-indesign-and-cross-references-to-them.php

I would use a live caption to get the image title.

You can get the section marker from insert special characters > markers > section

You will have to export the InDesign document as IDML in order to open it in an earlier version.

Actually, Adobe released Adobe Digital Editions (ADE) version 4 this week, which does support fixed layout epubs. Many people say it was released too soon (a bit buggy; doesn’t support fxl spreads, etc.) but it’s a good start and I assume they’ll keep updating it. And, of course, there are several other FXL readers, including iBooks and kobo, etc.

It might just be that font. See the info here about left and right side bearings:
https://creativepro.com/removing-space-along-left-edge.php

Also, in this case, I would not apply any letterspacing. Instead, take off the letterspacing/kerning/tracking and instead just select the “Justify All Lines” horizontal alignment. That should force the text to stretch from one margin to the next.

But again, most fonts don’t reach all the way to the left or right edge, so there’s a good chance that you’ll see extra space there in large sizes.

Interesting idea. But you can only link to URLs. Can you put the ics file on a server, then get the url of the file and link to it?