First thing is decide what data you have that can be readily replaced. e.g. publicly available Linux ISOs. Then remove that from your backup strategy. You may end up with a lot less data needing backup.

It’s on record that Gabe is very aware of Microsoft’s desktop dominance and ability to fuck up his gaming business. Valve’s push to Linux is strategic de-risking.

Yes. Just connect one moca adapter to your ISP’s modem/router via Ethernet. If the router already has a coax port you only need a single moca device at the other end. Then plug the coax cable into one of your home’s cable junction boxes. Your home’s probably got a cable splitter somewhere if you have more than one cable outlet. Unplug the cables you’re not using at the splitter. Now plug in another moca adapter at another cable junction box and wire that into Ethernet to distribute to your device, eg. Computer or network switch.