("…and now for something completely different") While thinking bluetooth, something that has nagged me for a while got an answer that may interest: if anyone else is bothered by BT coming visible/enabled by default after switching wlan on from HW switch, just edit /etc/bluetooth/main.conf and find the line AutoEnable=true and replace it with: AutoEnable=false. Some other settings there too.
The behavior seems a bit peculiar, as this doesn’t keep BT off at all times. At boot it still seems to automatically switch on (like going to some default settings, forgetting the .conf - not unlike screen zoom level), and if BT was on before you used HW switch to off, it will be back on when HW switch is used again (not what I’d expect). The small positive is, that now, if you have switched BT off (from SW, from top bar), it seems to stay off (unless reboot) when using HW switch.
Anyhoo, a minor improvement to security/privacy by default. (“Now back to your regular programming…”)