Well, there will always be another problem to solve, I don’t know if any software is going to be solving that any time soon.
I can say that the ebook output in version 3 is without doubt far more sophisticated and capable than version 2. A lot of work was put into that area, and it allows a level of control that few writing tools afford you. I don’t know about easier, considering that at a base level it means learning a major overhaul, in the middle of the final phases of your project. But speaking more objectively, and outside of your context, I do believe it makes getting things done easier, because it has more power and flexibility, which means if you want to do something, there is a greater chance you can do it without additional post-compile workflow.
Specifically will it solve these two problems you’ve raised? Yes. It is a style based program instead of raw formatting, like v2. You would apply a proper “Caption” style to the line of text beneath the graphic, and when doing so, it will create a semantic figure element in the HTML, with a figcaption sub-element, and apply CSS that binds the two together so that they don’t get separated between screen draws.
You see what I mean though—it makes proper captions easier than v2 because in v2 that would require manual labour after each compile—but for you it means going through your entire work and applying styles by hand to every bit of text you’ve given the appearance of a caption, in v2. So in the here and now, I’m not sure which is easier.
But that is a question you can answer for yourself. Download the demo and give it a 30-day spin. You don’t have to commit, you can open your project and it will create a v2 backup alongside when updating the format. If for whatever reason you find it isn’t for you, there is a command to export back to v2 format, so you can pick up where you left off in the old version.
As I say, compile has been overhauled, so in addition to going through the “what’s new” appendix in the user manual and tutorial, we also have a migration guide, specifically written for experienced users of v2, which maps the old concepts to the new ones in an interactive demo project.