I've done that more than once (note the list of things I tried in my first post). Flash player works in all other webpages with no problems. I'm beginning to think it's a problem with YouTube itself....
Maybe Flash is corrupted. Try using the uninstall tool at this link and then install a fresh copy.
A clean install would probably fix it....but I don't have the time, energy, or willpower to do one right now. Both of my computers will get clean installs before the end of the summer (like to keep a clean system), but I don't have the time for one right now. Too many exams and such coming up.
We weren't expecting cleaning the old Java out to fix my YouTube problem, but since it was there, we went ahead and fixed it anyway.
I don't know why you were pursuing the Java angle (I mean I don't know as in i don't know enough, not I don't know as in second guessing you lol) but JavaRa acts on Java like the Norton Removal tool works on Norton. Even though you un-install either one with traditional methods, crap gets left behind. If there is something in the Java that might have been blocking your youtube KeyboardNinja, it wouldn't hurt you to run Javara. At worse it comes up with a clean log, at best it finds something left behind. It doesn't touch the latest version of Java.
If anybody else has anything else to try that hasn't already been tried, feel free to share it.
If I can't get it fixed, I guess I'll just use Google Chrome to watch YouTube videos until my next clean install.