I have used your approach for some years now, it is so useful to be able to keep /home/user clean, if I want. It is also simpler to decide about data backup.
However, I went onwards from the partition idea and used separate data drives. I think I usually mount these after an install process, I cannot remember. They are connected in anyway before installation begins, and I think they get auto mounted from Places or in file manager nautilus when I later use Ubuntu.
But because I use the two drives all the time, well one is, but the other is used to contain a complete copy of the first data drive, taken once per day, I
configure fstab to permanently mount them. My fstab entry is:
I also run more than one installation of Ubuntu on the machine (different versions, whatever, on sda) so the common data drive is even more useful with that.
/dev/sdb1 /media/data-a ext4 defaults,users 0 0
/dev/sdc1 /media/bak-data-b ext4 defaults,users 0 0
An aside comment:
I know I am not using UUIDs here, but I do sometimes.....