[Fire HD 8 and HD 10 General] Ivorin:
I've kept my Fire 7 and Fire HD 8 on the stock launcher for now. For one thing, I didn't have much luck getting Nova Launcher to work consistently on the Fire 7 except for the very first time. Each factory reset after that prevented the launcher and hijack from working again, for some reason. Moreover I'm a new Android user; not yet a power user. So the standard launcher seems adequate for me, and might avoid the overhead of something more sophisticated.

Here's my complete list of hidden apps. Suggestions and feedback are welcome:

# Attempting to block updates (the fourth one might not exist on some tablets):
pm hide com.amazon.settings.systemupdates
pm hide com.amazon.device.software.ota
pm hide com.amazon.kindle.otter.oobe.forced.ota
pm hide com.amazon.device.software.ota.override

# Removing ads:
pm hide com.amazon.kindle.kso

#Removing preloaded apps...
#The below are kept because they're likely required for Alexa to work: Help App and Dee (Alexa-related):
#pm hide com.amazon.csapp
#pm hide com.amazon.dee.app

#Google Play Music is kept just to possibly provide basic Android music playback functionality.
#pm hide com.android.music

#Below is uninstalled because even if kept, it still doesn't allow the Fire 7 or Alexa to play Prime Music. Plus you can play Prime Music from a browser anyway via https://music.amazon.com
# Amazon Music (it can't play Prime Music by itself; some other component is missing):
pm hide com.amazon.mp3

#The video apps below have a pretty big memory footprint, both background and foreground, plus I doubt I'd ever want to play Prime Videos or other Amazon videos on this small tablet. Besides, there are probably much better video players out there, as well as the ability to play them in a browser.
# Amazon Video and My Videos:
pm hide com.amazon.avod
pm hide com.amazon.kindle.personal_video

# Weather and Maps (since there are better apps and sites for these):
pm hide com.amazon.weather
pm hide com.amazon.geo.client.maps

#The below are kept because the clock is probably stock Android, and the calculator is probably a simple but potentially useful app.
# Calculator and Clock:
#pm hide com.amazon.calculator
#pm hide com.android.deskclock

#Keeping "android.contacts" might be necessary to Allow Alexa to integrate with the tablets default Contacts app. The below are kept since they're most Android stock things and likely harmless.
# E-mail and Calendar and Contacts and FBcontacts:
#pm hide com.android.email
#pm hide com.android.calendar
#pm hide com.android.contacts
#pm hide com.amazon.dp.fbcontacts

#The below are kept to have some basic functionality and they don't seem likely to be bloatware:
# Documents and Printing and Downloads:
#pm hide com.amazon.zico
#pm hide org.mopria.printplugin
#pm hide com.android.downloads.iu

#Keeping "unifiedSearch" seems to enable both the home screen's search bar and Alexa's ability to perform web searches, though she often opts to search for paid videos and movies instead of general web searches.
#pm hide com.amazon.kindle.unifiedSearch

# Silk browser and parental controls:
pm hide com.amazon.cloud9
pm hide com.amazon.cloud9.kids
pm hide com.amazon.parentalcontrols
pm hide com.amazon.pm

# Profiles and Family Library App:
pm hide com.amazon.h2settingsfortablet

# Games and Freetime:
pm hide com.amazon.ags.app
pm hide com.amazon.tahoe

# Kindle Store and Amazon Appstore and Shop Amazon:
pm hide com.amazon.webapp
pm hide com.amazon.venezia
pm hide com.amazon.windowshop

# Books and Audiobooks:
pm hide com.amazon.kindle
pm hide com.audible.application.kindle

# Related to GoodReads and Twitter and Facebook:
pm hide com.amazon.goodreads.kindle
pm hide com.goodreads.kindle
pm hide com.amazon.unifiedsharegoodreads
pm hide com.amazon.unifiedsharetwitter
pm hide com.amazon.unifiedsharefacebook

# Amazon Photo and Photo Importer:
pm hide com.amazon.photos
pm hide com.amazon.photos.importer

# Items of uncertain function but considered bloatware:
pm hide com.amazon.platform
pm hide com.amazon.kindle.cms
pm hide com.amazon.client.metrics
pm hide com.amazon.client.metrics.api
pm hide com.amazon.webview
pm hide com.amazon.webview.metrics.service
pm hide com.amazon.socialplatform
pm hide com.amazon.advertisingidsettings
pm hide com.amazon.precog
pm hide com.amazon.ods.kindleconnect
pm hide com.kingsoft.office.amz
pm hide com.amazon.device.sale.service

# But the app below is kept for now. It's needed for Settings->My Account to work, not that that's essential. It might also allow Alexa, via the setting in her app, to display visuals to accompany her spoken responses
#pm hide com.amazon.kindle.otter.oobe

# Someone said it's a memory hog:
pm hide com.amazon.comms.multimodaltachyonarm

#Likely a CPU hog, but perhaps only when the screen is on and hands-free Alexa is enabled:
pm hide amazon.speech.wakewordservice