In Grayjay you can group your subscriptions. https://grayjay.app/

Have you measured the power consumption with a kill-a-watt (or similar)?

I am very happy with Blocky https://github.com/0xERR0R/blocky

No UI, just a simply config file if that is your thing.

Because that is how Bluetooth is specified. Bluetooth is primarily used for audio, where high throughput is not the most important parameter. Expected Bluetooth throughput is less than 2 Mbps, see more here https://www.bluetooth.com/blog/exploring-bluetooth-5-how-fast-can-it-be/

WiFi on the other hand, has peak throughput above 1 Gbps. So your observations are as expected.

Yes it is. But people can’t share files unless you allow it, or you create a user for them. I think everybody can share files using Send.