SRT have little to do with HDD RAID, but requires RAID mode 0 to function. It is best to RAID identical HDD's.
2) depends on if you use RAID 0 or 1 for HDD's. 3) TRIM will be on by default if the drive supports it and if you use an OS newer than XP. SRT drives do not support TRIM.
You should simply make a BACKUP IMAGE of your SSD (Windows etc) to one of your hard drives.
You can get a free version of Acronis True Image from the Seagate or Western Digital site (must have one of their drives for it to work).
For example, my SSD showed 50GB full. Acronis TI compressed this to about 25GB but it varies by how much RAM you have and how much pictures/video you have. (Acronis TI won't compress video or pictures. It also doesn't waste space copying your Pagefile or Hibernation file.)
I've been using Acronis TI now for four years and I love it. I always keep at least one backup copy and make a new one every month.