Any software you have for encoding is already licensed
That's not guaranteed. Most open source software isn't licensed.
and any non-commercial usage doesn't require a license at all.
Not accurate. Some, but not all, non-commercial usage doesn't require a license for the media, but the software still needs a license.
MaximumPC paints this a little bit different. Where only lower end cpu's get a big boost in conjecture with higher end AMD cards.
I was wondering how that made any sense, because I've never seen my i7 more than 20% used in any game where I've monitored CPU usage. However, I haven't played the Battlefield games in years.
CPUs can bottleneck even at 20% utilisation. The task manager will show 20% average utilisation, but that could mean that it sat at 100% utilisation for 20% of the time, rather than 20% utilisation for 100% of the time (or some mix in between).
Test your backups after you make them
it's a cheap and easy 99% solution
It's not a solution. It's a bare minimum requirement that doesn't solve for bitrot.
Honestly, I'd build two of these devices, one for local backups and I'd put one at a buddies house and do remote backups from your local device.
Oh what I'd do for usable upload bandwidth and reasonable data caps...
My understanding is that Storage Spaces is (as he says) MS's version of ZFS - does it not have the same data-checking features/ performance hit that 'regular' ZFS does?
No, it does not have the same data-checking features. Yes, it has a performance hit. Worst of both worlds. I've used it, and junked it as it was literally an order of magnitude slower than RAID5 via mdadm on Linux and didn't actually add any resiliency over RAID5 or flexibility as to grow an existing pool, you need to add multiple similarly sized drives since it doesn't rebalance. This is despite their marketing claims that you can add mismatched drives in an ad hoc fashion and have it "just work".
The only way to get Microsofts unproven resiliency benefits is to use ReFS in conjunction with mirroring (not parity) on the expensive server editions. Windows 8/8.1 does not support ReFS.
Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.