I'm sorry you're having such a tough time. But your experience is a cautionary tale for anyone who gets a bug up their butt to try something so ambitious. My guess is that anyone with the technical skills necessary to successfully navigate such a complicated task doesn't need to come here for help.
Do yourself a favor and buy a Mac or a new Windows machine. You'll live longer.
The only thing I can afford is free.
My financial situation is worse than you can imagine.
I can't seem to find my power adapter for my mac, which has all my virtual machines on it, so I can't test it right now. I think it's in the office - but my house is a disaster because of remodeling, so I don't know. I'll check my office when I go in this afternoon.
So, here's what I found searching. Here's my google query: flashplayer, firefox, ubuntu
The second link is to Ubuntu's help page for plug-ins:
https://help.ubuntu.com/community/FirefoxPlugins
That has links for all the popular plugins. If you click on flash player it brings you to a page where you can choose the different flavors of Ubuntu. Following the links eventually takes you here:
https://help.ubuntu.com/community/RestrictedFormats/Flash
I can't test it, but give it a shot. If it doesn't work then I'll see wtf I have to do to get it working on my virtual machine as soon as I find that damn power cord...
Yea I already had that "ubuntu-restricted-extras" from that first link you gave, and the vidoes still did not work.
When I used the 2nd link you gave, and then clicked on "Flash Links", it took me to that first link you gave.
Although, on the 2nd link you gave, there were other links on that page, that I wasn't sure if they were relevant.
In the first paragraph it states, "If you are using other, unsupported versions of Mozilla Firefox and would like to install or update plugins, see the Mozilla Browser Plugin Support Documentation. ". That links me to this page for plugins.
PluginDoc: Home
But there is nothing there for Ubuntu/Xubuntu. Only for Linux. Will the Linux files work ?
I have a similar question on Linux. Often when I go to play a video, it indicates the need for a plug-in, and sends me to this page.
http://get.adobe.com/flashplayer/
But again, when I drop-down on that menu, the closest thing I can find is Linux. I actually tried downloading all of those files, in case any of them worked. But when I extract the files after download, there is no exe file in the folder to install the plugin. So I assume that IF it works and it's the right file, then I probably need to enter the commands manually in Terminal.
Another thing I noticed is this.
I have another PC, in which I installed the dual Windows & Xubuntu. And the video works perfectly on that, just like it did on this PC, when it ran on the dual Windows & Xubuntu. It wasn't until I switched from the dual OS on this PC, to replacing Windows completely with Xubuntu, that I started having major video issues.
So I determined that the PC with the dual OS's that's playing videos correctly, actually has Xubuntu version 12.04.4 on it. While the PC that is running solely on Xubuntu, which the vids do NOT play on, is Xubuntu version 13.10
So, the older version is actually running better than the newer, as far as vids go apparently