@Subratabera, FireStarter is not a very good firewall.If you need a very good firewall,
then install
Shorewall. Configuring Shorewall is too geeky, so suggest that you
download
GUI tool for Configuring Shorewall from
here
With Shorewall installed & configured properly, you can prevent any application from accessing
the Net. Also read
Tutorial on Configuring Shorewall using Webmin (GUI tool) Click
here
Regarding installing Fingerprint theme, I think @Eddie can help you. Since I use only GNOME,