Disc chemistry will dictate the best burn rate. Or at least it has for previous optical media formats. Don't over-speed them, don't under-speed them. Choose a speed that it seems to like best and stick to it. I just let the drive choose unless I have some reason to override this. I have CD-Rs I burnt back in circa 2000 that are still readable. Good burner hardware and quality media is the key here.
So, what I would do in your case is this: Buy yourself the largest established HDD at the time. That is, don't buy a 4TB when they're new. Stick to the 2TB models for a while. This is how I populate my (home-built rack-mounted Linux MD RAID) NAS. When the 1TB drives filled up, I took them out and replaced them with 2TB drives. I then used the 1TB drives to back up the NAS. Since I wasn't losing 1/4 of my space due to RAID-5 overhead, this was pretty much enough until I filled up the 2TB drives. I'm about due to replace those with larger disks, and the cycle begins again. This way, you're not leaving drives for decades, but constantly refreshing the hardware. Just use a USB dock to copy from NAS to backup HDD, then store it somewhere safe. You don't need to bomb-proof the things, just put them somewhere they won't be disturbed, in the little plastic clam-shell the new drives came in.
It would also be wise to back up individual episodes (or a couple, depending on how much space it takes) on BD-R. Keep these in sleeves in a binder or storage box so you can go right to the material of interest if/when you decide to revisit old footage. If the disc fails, go to your HDD backup. This will keep the power-cycle count low on the spindle motor. The optical disc won't care how much it's used.
MD5Sums of all the data couldn't hurt, so you can tell if there was bit-rot along the way. But usually, the medium itself will have a CRC of its own at some level that will fail in obvious ways (read errors) so, meh.. Keep in mind, it's merely an alert that something has gone bad, not prevention, so consider the worth of that feature before going to any trouble. I do have a script that updates a per-directory md5sum on my media share for this purpose, so I can eventually write another script that compares this to the actual file checksums and lets me know if a movie file has gone bad.