[exaltedwombat]

You can force a new screen (use Split at Cursor) but you can't control where the content flow will spill over to the next screen. (And it will be at a different place for readers with different screen sizes, different choice of text size...)

So put a Split before a chapter heading. This will probably result in a short previous page. Tough. This is The Way Of The eBook.

Photo captions are another problem. There IS a 'keep together' HTML instruction, but eBook readers take no notice of it. I usually work on the principle 'if a photo's worth including, it's worth SEEING' and prefer full-page photos, i.e. put a split before the picture. If the picture's landscape, you can make it full width and assume there'll be room for the caption on the same screen. If it's portrait, do your best. If you're stuck into a mindset of trying to reproduce a printed page's layout on screen, well - good luck!

(P.S. Don't be frightened of Code View. It's where you can do the stuff you WANT to do.)