1 and 3: intriguing.
With 2, I'm trying to think how effectively it could replace something like ESPresense. With that you've got a BLE tag with an ID that you can just associate with a person, so there's no learning of moving patterns needed, but getting it to be accurate to a room is a nightmare. It also works when there's no movement, which is convenient, and you can put the tag down if you don't want to be tracked. The ergonomics are just a bit nicer, it's just the resolution that sucks.
ESPresense and TOMMY solve different problems right now. ESPresense tracks specific people with IDs (even when stationary), while TOMMY detects anonymous motion across zones. For your use case, ESPresense is probably the better fit currently. Though once stationary presence detection is added (Q1 2026) and person identification, it could do similar tracking without needing physical tags to carry around.