Mainly, I’m wondering if I should migrate /home/ to my RAID array, or leave /home/ where it is and create a new directory on the RAID array.
Leave home where it is. Symlink to important directories on RAID.
Makes it easier to mess with the RAID if it doesn’t make logging in hard.
I tend to buy two at a time. Some are months old, others three years old.
Professionally, I have seen drives over 10 years always on at low utilization without issue. (The data was easily replaceable.)
Heat is a killer. Check them regularly.