A lot depends on how many users you expect and how much media you expect. For one or two users with that stack, transcoding media is really the only CPU load. If most of your media is already in your desired format, then that’s not a big deal.

My stack is pretty similar (no *arr, plus tvheadend, homeassistant and a kodi frontend) for two users and it sits near idle all day long. It runs on an N100 NAS system off Aliexpress with 16GB and will transcode 1080p to x264 at just about playback speed… System runs from a 100 GB nvme, with a couple half-full 4 TB WD Reds for data. 35-ish Watts, maybe an extra 5 when actively transcoding. Used to be ~150 USD,

If you want a lot of 4k content, then I’d definitely go with the GTX 1660.

Same. Eventually upgraded to a Pi 4, which doesn’t have any trouble with 1080p content. Pi 3’s onboard wifi was also problematic, and I had to run it over wired networking. Kept that for the Pi 4, so I don’t know if its wifi is any better.

The likelihood that all cancers express a common surface marker that is never expressed by any non-cancerous cell seems pretty low. Not a cancer biologist, but there’s all kind of different genetic paths to cancer - why would they all cause some specific molecule to be expressed and why would no other cell ever use it?