Yes and No.

Whatever the “things/wheel” may be, it is to don’t care, whether it is simple/complex, as there is no 'interest/desire' in it.

“Living off the land”, yes it is. By roaming around, and whatever the food is, to eat, and even if there is no food, don’t are about hunger.

There is a difference in ‘vanaprasta’ and ‘sanyasi’. In case of vanaprasta, they care only about body, so hunt for that day, residing in forest, to stay away from external influences. But, in case of ‘sanyasi’, the next stage, you don’t hunt, but ‘beg’. If someone offers food, one eats. If not, don’t cares of hunger, and reside in city/village and not in forest

And In sleep, whether we "know/find out" - we are living/dead?, likewise don’t care of hunger too, and rely purely upon “That”, and if it is necessary, “that” will provide full energy to eradicate hunger

What do you mean by "self-sustaining"?