Phantasm — Having a 2 sec immunity is something we may consider, but we also don’t want snares in PvP to be quiet as prevalent as they are today.

Mind Melt — The timing of the Mind Melt buff interaction with Mind Spike sounds like a bug and will be fixed.

Shadowy Apparition — It sounds like there are a lot of bugs still with the implementation. The way we intend for it to work is that the Apparitions are shades of your character and will attack the correct target (the one with SW:Pain on it). We have already fixed several bugs relating to Shadowy Apparition interacting with Shadow Orbs and Mind Blast. (Source)