You want to move your drives to your mainboard because a lot of those cheap adapters suck. Unreliable and they can buckle under load. Can be a PITA.

If there is performance to gain depends on how accurate your information is, what drives you use, and how.

My backups are tiered. Some stuff gets no backup at all, some gets even more than 3.And I tend to reuse HDDs that got replaced in my main machine due to size for my backups. Power consumption hardly matters when it only runs for a few minutes a day.

Archiving modern websites is rather tricky. There are tons of servers involved and they often run some software themself. These are black boxes that cannot be archived without direct help from the web admins. For this reason, archived sites are often broken in some minor or major way.

Without a link, it is pretty hard to help you with your specific problem.

As I said this is something they cannot deal well with.

Only to carry a few files or whatever from one PC to another. They are just too unreliable, get lost or damaged too easily and their performance almost always sucks.

Unless you have to have your data always available a single 16TB drive will work just fine. ~£200 for the drive and it also consumes 10W and not 40. Likely pretty relevant in the long run in the UK.

And when you need more storage use Unraid or mergerFS+Snapraid on Openmediavault. They both allow you to add single drives of any size to add storage capacity and parity. ZFS is great but it kinda sucks as a home user as expansion only works well when you add 6 or even 12 drives at a time. At least for now.

Get a NAS. Unless you are tech savvy and dedicated get a Synology. You can get another Synology or hook up a USB drive for backups.

To backup and manage your photos you might run Immich in a docker. Although some people also like Synology's own solution.

because I always write 100% full random data on the device before using it.

Do you mean before every use or after receiving it?

When you continuously write to a consumer SSD they will slow down for a while. They are built for short burst of writes because that is what most consumers do. For continuous fast writing you need better NAND, a better controller and better cooling.

for a very long time

Long term digital archiving is not really a solved issue. Your best bet is an active approach with multiple copies that are checked regularly.

Is this your boot drive? If so it should have been replaced by an SSD like a decade ago.

This is a bit overkill although it depends a lot on what you will use your VMs for.

I would make sure you set a TDP limit for the CPU. Some board makers totally disregard Intel guide lines and allow the CPU to pull like 200W+ continuously at full load. Limiting it to ~120W will not cost you a lot of performance but might save some power.

650W is total overkill unless you add a ton more drives. Gold PSUs are not rated below 10% load. Here they can drop to 50% or less meaning a gold 650W might consume more than a Bronce 350W unit.

I am personally not a big fan of ITX builds. You can only add a single PCIe card. And you might want to add an HBA, NIC, GPU (for transcoding), NVMe SSDs, or something else down the line. With an ITX board you can only add one. And this PC is not small anyways.

The key to keeping your data longterm is not RAID. raidisnotabackup.com Unless you run a critical server 2 drive parity with 3 total drives is total overkill.

If you are fine with a bit of downtime during recovery I would not bother with RAID at all if you only need a single drive to satisfy your storage needs. Only when you have multiple drives being able to resilver rather than restore is worth the premium. You might want to get a new drive as they do not cost that much extra and will likely live a fair bit longer so they do not cost anything extra in the long run. You might use some of those refurb drives for your backup server though.

"Best" is usually a vague term. Best would be likely a high end enterprise SSD. Costs about as much as a car but is reliable and pumps out data at multi GB/s speed all day long.

How much storage do you need?

How big is your budget?

How fast does it have to be?

How large are your games usually?