Luftwaffe Customs and Courtesies

[Broncazonk]

Right now I am interested in Luftwaffe customs and courtesies, particularly saluting and cover requirements (hats and caps.)

For example:

1) Was saluting ever appropriate indoors?
2) Also, was a cover ever worn indoors?
3) And, did a person ever salute while uncovered?
4) The cover was mandatory while outdoors, correct?
5) What about saluting on the flight line?

6) The "Heil Hitler" salute became mandatory sometime in August, 1944 (after the July 20, plot?)

7) When was the "Achtung" command used in the Luftwaffe? (Inside only, never on the flight line or repair shop, correct?

Does anyone have insight or a source?

Thank you!

Robert