When IFR, ATC probably won't let you cross the Alps (or anything else) if you are below their MVA.
When VFR, they couldn't care less
And if you have to fly below CAS (Class C usually), it gets "quite" close especially on the routes down from Switzerland...
Anyway, I can't see how TAWS / EGPWS would be of use in terrain avoidance. You don't get a very good picture from it, and the database can be somewhat suspect. If one is going to be a real cowboy, one will run a copy of FSX or X-Plane in the cockpit, with the ex-NASA SRTM DVD terrain set, and feed the NMEA GPS data stream into the computer running it
I should think that, in Africa, anything goes. Especially in SA where men are still real men.