I would recommend prowlarr instead of jackett for indexer management, and pihole as at least an additional blocking service but in reality it’s really all you need for use at home. I’d also strongly encourage use of a VPN on your *arr download services. I use a separate box to run Plex and then have my *arrs all running on their own VM inside if it to provide separation and allow be to more easily segregate the network traffic (as someone that doesn’t really know docker that well it “just works” for me. Also probably worth looking at how to store your media on an external target, it’s easy to quickly accumulate 10s of TBs of media and trying to store that all on the server locally is asking for trouble. Better to set everything up on a NAS to start.
The reality is they may not know exactly what was obtained, but they do know it wasn’t anything they don’t collect (like DOB, SSN, etc listed in the message). Instead of looking at this purely as a CYA message, instead looking at it as informing you as soon as they had any idea your information may have been impacted instead of waiting weeks/months to inform you. Don’t let perfect be the enemy of good.