I installed Fallout 3 on linux, wondering if anyone else has had a similar problem. The facial animations and voice acting don't match up, it seems the speed of the animations is faster than the voices. It's not a huge issue, game is still as enjoyable but if I can fix it I would like to.

Yep, I experienced this (as I recently installed it). It's not your Linux, as I'm on Windows 10. The issue is around the framerate. When it is too high you'll see some animations, and in particular lip-synching, running too fast.

Applying a cap of 60 FPS to fallout3.exe worked for me. However, it might be possible for you to edit your FALLOUT.INI to get it running at high framerate without the animation issues (not sure if this would also fix any physics oddities, though). If you do edit your FALLOUT.INI file then look to change the values of the following:

iFPSClamp
iPresentInterval
fMaxTime

For instance, try using your monitor's refresh rate for iFPSClamp, set iPresentInterval to 1, and set fMaxTime to a value of 1 divided by your monitor's refresh rate (go as far as 4 decimal places).

If editing the FALLOUT.INI works, you might want to back it up and set the file to read only to prevent the game overwriting your changes.

I ended up reinstalling the game and the animations were no longer a problem. However I'm having a problem getting saves to load and all of the ambient music (and maybe radio music, haven't gotten that far...) is wonky and out of time.

I did see a lot of threads with that fix, though, and thank you for sharing here, too.