No, they are hardened and can be used like steel nuts, although you have to be careful. Using a torque wrench rather than a windy gun or long lever is a good idea.
The nuts on the 911 weigh close to nothing and as you say it is unsprung weight.
Not sure if they had air guns in the seventies but it best to tighten them up with a torque wrench and in some kind of sequence like a cylinder head.
Not very good for quick wheel changes though and you do need the right vehicle to be worth doing
No, they are hardened and can be used like steel nuts, although you have to be careful. Using a torque wrench rather than a windy gun or long lever is a good idea.
Not in the same way, agreed, but precipitation hardening, also called age hardening, is a heat treatmenthttp://en.wikipedia.org/wiki/Heat_treatment technique used to increase the yield strength of malleablehttp://en.wikipedia.org/wiki/Malleable materials, including most structural alloys of aluminium, magnesium, nickel and titanium.