If I really need data backup, I can use one of the other SSDs or even the single spinning disk I put in as a backup target.
2) That's interesting, I don't think the noise comes from the PSU though, mainly the six case fans.
3) True point. I'm not too worried. The machine is fully supported by Linux (no drivers required) and the latest SPP is applied. I never expect to do hardware changes/upgrades down the road. And in five year's who then lives, deals with the shit ;-)