The rocks in your examples are not playing surfaces. You'd play each of those as if they were a small bush.
If your disc were near the front of #2 and you wanted to jump up on the rock, I would expect your card mates to accept that, however if you said you wanted to mark behind the rock on the LOP, I would also expect the card to accept that as the lie.
Where are you getting that rocks aren't part of the playing surface? We take stances on rocks all of the time. You can place a supporting point on the rock, it can support you.
802.05 Lie:
A … The playing surface is a surface, generally the ground, which is capable of supporting the player and from which a stance can reasonably be taken. …
802.07 Stance:
If the lie has been marked by a marker disc, then when the disc is released, the player must:
1. Have at least one supporting point that is in contact with the lie; and,
2. Have no supporting point closer to the target than the rear edge of the marker disc; and,
3. Have all supporting points in-bounds.