Recording calls was possible on pretty much any Android phone until google killed the accessibility API in May 2022, since then at least Google and Samsung phones can still record calls, it's just disabled in some countries for legal reasons, but people then buy phones from other regions on ebay/other similar platforms. It's been a "thing" for years.
1. Dialing in the dumb phone. No dumb phones support CardDav syncing.
2. Very few dumb phones can function as wifi hotspots for the e-ink device.
3. Few dumb phones can record calls.
4. I forget what eight was for... seriously I had one or two other issues but I don't remember what they were.