I have been using this Rom on a daily basis since the tutorial was posted -- and have added a number of apps and customized to my personal preferences. I've had no issues at all -- with either Amazon or Google apps & services! THANKS once again to all who've contributed!
PS: for convenient switching between launchers, this works well for me: installed Apex launcher with its tablet UI - and set it as default launcher. I have the Kindle "Home" icon (shortcut to stock launcher) on my homescreen - hitting that goes instantly to the stock Kindle homescreen - and hitting the device's home button will get me back to Apex/android.