theteju, i can't find a place to put files, since it's not that big, i'll attach it to this post. Hope the admin's don't mind.
Changing the nvidia-install.sh script on your md will not break your install, and i said make a backup before doing so.
I would try:
* change the nvidia-install.sh to just exit (make backup first) This way the 195 driver will not be re-installed on reboot
* install latest nvidia driver (see above to kill X, etc.)
* reboot with /usr/pluto/RebootWithAVWizard.sh
If you still have no sound and alsa is still not there, install alsa through apt-get install.
If you need to upgrade alsa, here is a script that does that, it's a little dated, but can be adjusted to the newest.