It sounds like the kernel is messed up. I would run fsck and see if it fixes the
errors. What gives me a good clue is that FF is not working right. FF is tied
into the kernel and if you uninstall FF it would break your system. You could
try reinstalling FF in synaptic, but do not uninstall. You can run fsck in the
terminal. If all fails, just do a clean install. Practice is all ways good.