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If you absolutely don't want to risk taking a lift down at the end of a ski day, then you need to choose a high altitude resort, Tignes for example. Even then, the home runs may be busy and rock hard, so taking a lift down will seem like the sane choice.
For low lying resorts, which are often pasture, I reckon you can get away with 15cm on easy home runs, if you head high, then much more snow base is needed as the terrain is much more rocky.
As for heading off the sides of pisted runs, there is no such thing as a little bit off piste, so make sure you have adequate insurance, and accept that no-one will have spent the summer making your route safe.
Scope out where you want to go 1st, it's unsafe to follow other folks tracks, as they may go over a cliff!
Pistes are prepared in the places it's generally safe to go, if you head elsewhere be properly equipped and know how to use your kit.