I’ll leave the finer details of X & media management to those more knowledgable than myself, but some general RAID comments –
-To have all my current projects in one place (like the aforementioned RAID drive)
Make sure you use RAID 5 or similar. Do not use RAID 0! Drives WILL die. At the worst possible time. I’ve used parity RAID systems since the days of Quantel, and I can’t remember how many HDDs have died on me over the years. Your attitude must be “yeah, that single disk can die & it won’t screw me totally”. Carry that thinking across every drive you use & you’ll sleep easier as your projects get larger ($$).
-To be able to archive an old project and all its associated files from the RAID to cheap desktop Hard drives
And here, use RAID 1. (Separate array for archiving.) For the same reason as above. I’ve been archiving this way for 5 years. Got about 12 pairs of project archive drives on the shelf. In that 5 years, 1 drive (of a pair) has failed to mount when calling up an old file. No worries, reach for it’s twin, get file, buy replacement drive, mirror data to return to redundant state. I use a cheap “toaster” bare drive mounter. Just stick the bare archive drive into the “toaster slot”, get what you need, eject, done. Very fast.
Play safe! 😉