"I figured out that I can download some gif that don't work right off the
bat.
It's annoying, but acceptable (maybe I could automate through scripting that
it opens in a new tab after the download or something)."
i don’t know why your having problems heres me looking at cats:
http://92.19.232.58:82/files/cat_gifs.ogv
do you have the same problem on other browsers?
"Flash videos" + "I'm willing to try the other plugins, but aren't they
offering the exact same functionality?"
this is a video covering alot of plugins you can use to view flash videos
without non-free software:
https://goblinrefuge.com/mediagoblin/u/onpon4/m/tutorial-watching-videos-without-javascript/
"I still ca download the videos though."(asssuming you ment cant download
videos)
you should also try to use youtube-dl-gui incase for whatever reason you cant
view a video with viewtube:
https://trisquel.info/en/wiki/play-videos-without-using-flash
