The first thing to fix is the drive running. After startup, open a terminal and run "ps -e" to see what processes are running. Also, try "top".
I don't know what the issue with sudo might be, but I prefer to never use it. In Ubuntu, the root account is disabled by default, but can easily be turned on with "sudo passwd root". (Yes, you will have to get sudo working to do this**) Once the root account is enabled, just enter "su" to get into super-user mode.
**If you need to get things working without fixing sudo, you can get into the root account by booting into single-user mode. At the boot menu, go into edit mode, and add "single" to the kernel line, and re-boot. The system will come up in the root account with no password required. Then you can enter a root password using "passwd".
The alternate method is to boot from live CD and edit the /etc/passwd file. The edited entry for root will look like this:
(Removed the character between the first 2 colons)
This allows login to the root account with no password.