Fluff: Witch-fires should be focused (snipe the fallen), maledictions should be leadership based/ weaken enemy mind (interrogation), blessings should be defensive (stubborn, hold at any cost)
PP. Mind worm is OK, but could be 18" like almost all witch fires. And to many layers, get it off, not blocked, to hit, to wound, fail invul. save, fail feel no pain.
1. Seed of Fear is OK, but why malediction 9" bubble. 3D6 on all enemy leadership tests would be great, not only fear-, moral- and pinning tests. Situational, you will need to bring the librarian very close, no effect against fearless units.
2. Righteous Repugnance is OK, could be +1 attack in first round of combat (also defensive)
3. Aversion is the best power (malediction, 24", target unit can only snap fire, WC 1). Very useful and reliable.
4. Maelstrom of Misery, I dislike this (witch-fire, small blast S1 AP2, wounds on 4+, WC 2), very situational (bunched up terminators without storm shields in the open) and unreliable.
5. Trephination, I strongly dislike this (focused witch fire, 2D6+2 against leadership, WC 2) very weak psychic shriek that can kill maximum 1 model no synergy with Seed of Fear.
6. Mind Wipe OK, WC 3 is too much, unreliable. What it does is reduce enemy BS to 1 for 1 turn (same as Aversion for WC 1, but weaker BS 1 is better than only snap-fire) and WS to 1, with a small chance to make it permanent. No synergy with Seed of Fear. Could be great if the effect lasts longer (lets say for D3 turns) or the leadership test to make it permanent could be de-buffed with Seed of Fear.
The general problem with focused witch-fire is: it can only effect 1 model not a unit. And you need 1 more warp charge to make it focused (WC 2 you need 3). A viable target for mind worm (independent character) can look out sir. A focused witch fires with WC 2 is not good.
Summary: In my opinion only Aversion is excellent, Maelstrom of Misery and Trephination are not good, the other powers are OK.