How to enable video autoplay on Fire Tablet? Solution can include hacking this device
Well after a few hours of tinkering around, I figured out how to do this.

You have to use HTML5 video, so that is one thing. Then you need a mobile browser that supports auto-play, so FireFox needs to get installed.

This is tricky, because you need the Google App store, so you need to install that. That requires going into developer mode, then installing a script that will install google play. Then you can install Firefox and voila, problem solved.

I went ahead and rooted it, blocked ads and blocked updates as well because it works way better that way. 

This link below shows a video on how to root your Fire tablet and do everything I did:
https://www.youtube.com/watch?v=sVv1D_LNLTg&amp;feature=youtu.be