You can remove the firewall with: sudo apt-get remove --purge ufw
(Didn't find any point in using UFW, you can still use iptables (its a wrapper anyway)).
Also, you can try disabling barriers. Its a mount option for ext4. Will make it much faster, but if you encounter a power outage or something, you may lose data. So think. (To be honest I use it with that , I had some power loss, etc, no file loss at all). But I warned you. :)
So. Open /etc/fstab.
sudo nano -w /etc/fstab
And search for the "defaults". Change it to
noatime,barrier=0 . Save the file and exit (ctrl+x, y).
There is also an another entry with "remount" in that field (where the other had 'default'). Write it like you put a comma and write the noatime stuff behind. Like this:
errors=remount-ro,noatime,barrier=0 (not sure if the 'errors=remount-ro' is the one what you'll have, just check it.)
ASK if you dont understand something, ASK if something is not like I wrote. :)
About the net speed. Check /etc/resolv.conf >>
sudo nano -w /etc/resolv.conf . Type in the OpenDNS addresses:
nameserver 220.127.116.11 . Save the file, exit.
ALWAYS BACKUP THE ORIGINAL FILES! You can do that with nautilus (just copy the originals into your home) OR with
sudo cp /etc/fstab /etc/fstab.old .