I always use epubcheck, it's fired off automatically by our built tool.. and no errors or warnings. (this project is epub2, hence using pageList)
Prob not going down the ADE page-map route as the cliend will be uploading ro Amazon and no telling what that may throw up!
Yep on the previewer not showing page numbers.
Amaon say in:
https://kdp.amazon.com/en_US/help/to...g_page_numbers
" Real Page Numbers cannot be previewed in Kindle Previewer or by sideloading, but they are visible when your eBook is published and are mentioned on the detail page. "