1. These aren't the actual jedi, think of it like an echo from what Fused Ivrine did. We know this happens because every time there is a major force "event" it tends to leave a mark.
2. There is a really big differnce between revenge and justice. Fused Ivrine is being punished for what he did, the mode of that punishment comes from his own subconcious and is simply vented by Sophae's ghost.
As a more general point about interaction Kun broke Corran Horn's arm in I, Jedi.
3. As to Sophae's motive, she doesn't want her son dead. Plus Fused Ivrine is a Dark Jedi and must therefore be destroyed. (Touch of Agamarian there.)