send-to-Kindle only works with MOBI, not AZW3. That being said, Amazon doesn't make a note of it... but you can send dual-MOBI (contains mobi7 as well as KF8 content for graceful fallback on older devices) and Amazon will split it and serve you KF8 on supported devices.
If plugboards are defined in calibre, they will be applied on emailing as well... but unfortunately plugboards do not support dual-MOBI.
emailed books will have their notes synced.
Don't bother setting the ASIN or cdetype. All books that pass through Amazon's Personal Documents service automatically have certain post-process filters applied to force the book to appear as a PDOC.
