First scenario:
A1 order to move to X, but bounces.
A2 order to move to A1, supported by A3
all hold because you can't dislodge yourself. I'm sure of that.

Second Scenario: Add
B1 moves to A1, supported by B2.
Normally, A1 is dislodged. But B1 would be bounced by equally supported A2. So I believe all hold. Is this correct?

Third scenario:
C1 supports A2->A1. A doesn't ask for this support, but cannot refuse.
A3's support doesn't count, since it can't dislodge. So all still hold, correct?

Fourth, and most interesting scenario: B doesn't move at all.
A1 bounces. A2, supported by A3 AND C1, moves to A1. Does A2 dislodge A1 because of C1s support? Or is it true that you can't dislodge your own piece, EITHER by support or move?