Hey , FibreOS is optimized to be fast operating system with quick access to Your cold storage.
However You can install in it anything You want.
Here is the link and install instructions for Nemo file manager
http://www.noobslab.com/2013/10/nemo-file-manager-with-extensions-for.html
Here is the link also with instructions for Tor browser
http://www.enqlu.com/2014/04/how-to-install-tor-browser-bundle-in-ubuntu-14-04-lts-or-linux-mint-17-via-ppa.html
OK, Thanks! I will check those out. Another question, is it possible to encrypt the entire usb drive and still boot from it?
This is on the FibreOS Road map!! It is at the bottom of the list as their is inbuilt encryption functionality. However, I have bumped it up the list due to you requesting it.
Regards
Killa