Nuvi

Portuguese resident here, check out https://www.kuantokusta.pt/ for a great price comparison site which includes lots of stores. Also keep in mind that stuff travels freely without tax between countries members of the European union so it might be worth it to get some stuff from the german and uk amazon stores for example. Also where are you headed? Lisbon? EDIT: I buy mostly from PCDIGA for their great support and some competitive prices, thought I should refer them

To be honest I would keep them. You are entitled to keep the headphones if you don't contact them as it's illegal to bill for unsolicited items. If you do contact amazon It's likely they will only send you the item you ordered and a prepaid return label for the headphones. You would then have 30 days to send the wrong item or they will bill you for it.

You could also buy an external fan controller like this one which plugs in to AC and let's you control fan speeds

You don't HAVE to do it, as you can use it as 2 separate drives, C: would be your windows volume (M.2) and D: your data volume (SSD), you could acess files on both drives without further configuration. If you would like to make windows think it is one drive just search the web for how to create a spanned volume (sometimes called concatenated disk) on your version of windows

I suggest you install Intel Chipset Utility driver reboot and then reboot again without the USB inserted

System specs? EDIT: Also does de system boot in safe mode?

Yeah it is! ZFS scrubs for exemple offer great protection against corrupted bits, unless you use bad RAM in which case ZFS will attempt to "fix" corrupted data that it thinks is from your hard disk and write that data back. But instead it is actually reading good data from your drive, corrupting it in RAM, and then writing the "fixed" data to your disk, trashing your pool along the way... I suggest you read this for a detailed explanation if your interested, and here is an example of one of many people who experienced data loss for using bad non-ecc RAM

The freeNAS forum is the perfect place to read this but remember, ZFS itself functions entirely inside of system RAM, if your data is critical I'd keep away of non-ecc RAM. If you still decide to go with non-ecc ram test it really well, bad ram can and will make your pool unmountable and then there is no way to get any of your data back.

What do you mean by combine them together? Perhaps RAID 0? If that's the case have in mind that one drive failure = loss of all data. I would say just install de OS in the M.2 drive as it's probably faster and use the SATA SSD for data

That build is reasonably well priced (especially for an european location) but it's definitely not a gaming rig... God for a NAS build