1: Split
2: Yes I do... more actually! Also, yes, I have done the math, and I will hit 1PB in the next 3 years.
3: Not much actually... you would be surprised
4: Yup
5: Copy over. Update once a week.
6: My budget? Well, I buy 5TB drives at 90 bucks, and 6TB drives at 120 bucks. Not a fan of...