[Fire Q&A, Help & Troubleshooting] Nazo:
I guess the best thing to do is to edit that batch file to not completely remove a few basics like the Amazon app store itself. I didn't really understand why it removed everything Amazon entirely, not just the actual bloaty stuff. EDIT: I guess this is worth the effort anyway because it's removing stuff like the standard Android contacts even. Not sure why they'd do that. BTW, if anyone else decides to do this it seems "Venezia" is the package for the Amazon app store.

EDIT2: Waugh! I got a bit tap happy there after a factory reset. I tried to hit the "continue" button more than once because it was so slow to load the next page I thought I mistapped. When it got to the wifi selection screen there was at least momentarily the "not now" button available and because I had tapped that extra time in that exact spot it actually went through to the "not now" button and let me skip the setup... So now it doesn't even have a configured WiFi and still let me get to the home screen and everything. This is sort of a better way to anyone who can manage it.

Maybe this method actually requires an initial setup -- maybe it sets some bit somewhere that doesn't clear with a factory reset. Since you can factory reset from the recovery menu, I imagine you could try this if it manages to download the update and reboots to apply it. (Well, I guess the question is if it applies before or after the reboot, but I'd have to assume after since it must surely modify things that are in use.)

PS. After this factory reset I see that it definitely never let an OTA update through. It's still on 5.4.0.0. Well, I suspected as much but couldn't verify before. Since it has no wifi even configured this time around it doesn't even know there is an update waiting just yet. I'll fix that soon enough. :-p

EDIT3: I made a modified version of that batch file where I tried to identify things a bit more and be slightly less extreme in my removals. I used pm hide on a few where it's slightly more questionable since it's not as hard to fix as an uninstall (though, as discussed it's questionable whether they'll actually STAY disabled.

I read that "hide" is a bit more thorough in many ways though and the ones I used hide on I think are slightly less likely to bypass the disabling.) I don't see why the original creator removed some very basic Android apps like the e-mail and clock apps. There are alternatives, but these are as small and minimal as it gets, so it seems pretty weird and extreme to remove them. (I would definitely say it would be better to disable even if you don't want them.) While I was at it I did a hide only version since that's "safer" overall, though a lot of stuff may still bypass it obviously. (It may be best to actually remove the updates rather than hiding them.) I didn't feel like making a more thorough one that actually asks on each or something. (Going for minimal work here, lol.) The hide version seems to not work though atm and I have no idea why. (It only shows the status for a few things and most of the icons are still there despite a lack of any errors.)

Input is welcome since I just modified their batch file as simply as I could and was very unsure about a lot of things.