Alright, for the Firefox problem, since the file manager is crashing, try this.
After you've downloaded the Firefox install file, open up a terminal. Change to the directory in which the file is located. Then type in:
Code:
gzip -d firefox-1.0.4.installer.tar.gz && tar xvf firefox-1.0.4.installer.tar
...and hit enter.
After doing that, type
and hit enter to make sure there is a directory named "firefox-installer". Type
Code:
cd firefox-installer
to get into that folder. Now, type in
Code:
./firefox-installer
and follow the steps of the installer. Remember to make note of where the program installs Firefox so that you can access it later.
Once you have finished installing Firefox, close out of the installer and the terminal window.
And voila! Firefox is installed.
Hopefully this works for you.