Resurrecting and commandeering this year-old thread since it has been a year and there are now even more questions, at least for me.
You can in theory open ePUB3 files in ADE 4.0.2. However, at least in my experience, ADE still does not properly display fixed layout ePUB3 files, even when files do validate and display correctly on actual tablets and devices. Full spreads are inexplicably ignored in favor of displaying single pages. Fixed live type is sometimes not displayed properly.
I'm sort of scratching my head with this latest release. There are so many things ADE badly needs and promises, but doesn't seem quite there. Has anyone had a better experience with getting the latest version of ADE to render ePUB3 fxl?
Adobe is at least on the right track with things like support for audio and video content. I love that you can now add highlighting and notes, a great feature for developers sharing files amongst clients or other coders, but it is difficult to retrieve the notes once you've clicked the "save" button.
If anyone at Adobe's eBook team is listening... please do what you can to make this little app work as the latest release intended! It is a badly needed testing tool, and even more so for those of us attempting to develop FXL from INDD CC straight to ePUB.