Just my thoghts off the cuff, but I believe they reflect the current policy and etiquette.
I certainly don't ever recall saluting an officer's wife and wouldn't unless she were herself entitled to it. What if your were a sqn ldr and the air cdre were married to a flt lt?
Saluting entering an officer's office yes, irrespective of relative rank. I do find it a bit odd that some places (SHQs in the main) feel the need to have a sign that says words to the effect that 'headdress is to be worn in this building...'
Commissioned officers being saluted in or out of uniform is still correct and whilst stn cdrs and air offrs normally have flags and plates on cars, there is still a requirement to salute someone you recognise in a vehicle if you would normally be required to salute them outside it.
Wearing headdress in civvies was always intended to allow a salute to be returned (by raising the hat in response).
STH