D1398342003

You cant "expand" a VDEV without destroying the data, except perhaps a Mirror. But if you want to build something more balanced like a RAIDZ1 or RAIDZ2, then you need at least 3 drives, and to build a new VDEV, add it to the pool, then move your data across and destroy the existing one.
 
You've been watching to much LTT to be dangerous. Don't use a dedicated Metadata drive. There is absolutely no need or benefit with such a small system. Even if you had a 20 disk array, there would be very little benefit for 99% of cases. Its benefit beside faster file listing is also faster deduplication. 
 
Instead you could use that for L2ARC or SLOG, but this level of cache is quite unnecessary for most home users. 
 
You're probably best just to leave the SSD in its own separate pool. Say you have something like Plex, then chuck your AppData on it, or if you run any other Dockers or VM's use it to host those (dont forget to back it up as well). Ideally you'd want at least a mirror with SSD's as well. They can still die.  
 
 
Im pretty certain that isn't a thing with special vdev's. You're setting yourself up with a SPoF (Single Point of Failure) by doing it, regardless of how you build out your storage vdev's. You really need to have redundancy in your special vdev. 

I believe it can only be done with a basic (single drive) vdev using attach but yeah for any sort of redundant array or multiple vdev's it's a no. You have to create additional vdev's which you can add to the same zpool. 
 
No you can add a special vdev to an existing zpool. Theres an article on Level1Tech (Wendell's site) about it: https://forum.level1techs.com/t/zfs-metadata-special-device-z/159954
Removing it is the issue, or if it fails. 
 
I find UnRAID quite a handy solution for a lot of things and theres a large community that you can ask. It's very much community supported like Ubiquiti

Well, I just washed my old Walkman NWZ-S764. It would be more accurate to say that I had it in my pants pocket while it went through the wash. It's obviously now non-functional. Annoyingly enough I've done it once before, to another of the same type of Walkman.
 
So now it's time to buy a new one, and I'm not really liking my options. Most of the new models have touchscreens, which are about 95% incompatible with smooth operation through a layer of denim. The A20 and E395 both have buttons, which I prefer. I like the A20's control diamond, and that the 'Back' and 'Option' buttons are further away from it. I'd be able to accept the E395 if needed though. I'd be paying 3x the cost for slightly better controls, better sound file compatibility, and SD expandability.
 
My main question is if they have song navigation by folder. My old Walkman had sorting by things like Artist, Genre, Album, ect. It's a feature that was not very publicized, but existed. Is this feature still present on either of these players?
 
Secondly, I've heard some complaints that the E395 has bad battery life and slow something, UI or song navigation maybe? I'm not sure if these complaints are valid.

You'll need Microsoft's NVMe hotfix. https://support.microsoft.com/en-us/help/2990941/update-to-add-native-driver-support-in-nvm-express-in-windows-7-and-wi
 
Either bake it in with software like NTLite, or install Windows on a SATA drive of some sort, install the hotfix, and clone the drive to the SSD

Who is telling you ryzen makes lots of heat???  the stock cooler on the 1700 is both RGB and enough to OC it anywhere from 3.7Ghz to 4Ghz if you get a good chip.  A 120mm rad is almost overkill
 
 
1600 has same cooler but no RGB
 
Rather than getting a X52, jump to ryzen now and see if you're even close to needing the upgrade.

Sounds like it's liquid moving/bubbling, or fan noise to me... if I had to pick one I'd say liquid moving. That's louder than my 120mm AIO for sure, and AFAIK pump noise usually tends to be more of a buzzing sound, at least in the case of my AIO it is anyway.