I can answer on the Psychic:
Demon is better for pvp: you have faster channeling, you have more attack, Sandurst Blast lowers earth resistance for a few seconds, demon bubble has less cooldown then sage so you can spam it more to keep yourself alive etc etc etc.
Sage is weird, it's like it works better for "squad" type situations like, Aqua Cannon has a chance to Immobolize the targets that get hit with it, sage bubble purifies everyone in range, soulburn lasts a few seconds more then demon etc etc.
Depens on how you want to play your psy, do you want to be the tank and attack everything head on or do you want to hit hard and help support your friends out in pk?