Re: redirected home folder
What you need to do is to mount /dev/sda3 into /home and change /etc/passwd back to what it should be (because your home directory will be literally mounted under /home/<username>
So, change the /etc/passwd entry, go into /etc/fstab and create a new line there mounting /dev/sda3 to /home/ and reboot.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.