VAT is applied to all goods irrelevant of origination. Think of it as a federal sales tax instead of a state sales tax.

There are different rates dependent on the goods and some items are VAT free (again this has nothing to do with origin but to do with the product} i.e. I’m fairly sure that in UK children’s clothes are either exempt or VAt at a lower rate.

My home media server is an old nuc mini pc i5 16Gb RAM with attached usb storage running on a Linux distro, runs Jellyfin and a few other applications for the household.

In short yes, an old pc will work fine.