I've totally removed the BT icon from my bar.
I leave WiFi and BT always on and rely on the tablet switching them off automagically whenever they are not used.
The only thing I do is to put the tablet in offline mode as THAT is the only way to KEEP it from automatically looking for connections when I am sure I don't want it to connect (or I am sure I am going in a place where no network as been before..ehm.. where no network connection is available [either cellphone of WiFi]).

So far, the tablet battery has been lasting a lot.