Are these new powers balanced?

[the Jester]

I'm still trying to get a sense for balancing powers in 4e. I haven't really created many yet- I'm nervous about introducing them into a game that I don't completely grok the design rules of yet. I'm still kind of feeling my way out.

Anyway, these are conversions of older spells, feats, special abilities, etc. in my campaign. I'm especially interested in feedback on Bonebreak- a penalty that lasts all encounter or until you spend a healing surge seems pretty good; is it too good for a 9th level power, even one that is as low damage as Bonebreak is?

Thanks!

Thunderous Blow--- Cleric Attack 23
You bring your weapon down on your enemy, and a peal of thunder echoes from the blow, blasting your foe from its feet.
Encounter--- Divine, Thunder, Weapon
Standard Action--- Melee weapon
Target: One creature.
Attack: Strength vs. AC.
Hit: 2 [W] + Strength modifier thunder damage, and the target is knocked prone.
Miss: Half damage.
Effect: The target is deafened until the end of its next turn.

Bite Spirit--- Wizard Attack 1
You attack your foe’s spirit, leaving them wracked with agony.
At Will--- Arcane, Necrotic
Standard Action--- Ranged 8
Target: One creature.
Attack: Intelligence vs. Fortitude.
Hit: 1d6 + Intelligence modifier necrotic damage, and the target is dazed until the end of your next turn. Increase damage to 2d6 + Intelligence modifier at 21st level.


Bonebreak--- Wizard Attack 9
You point your implement at the enemy, and it shrieks in pain as one of its bones cracks and breaks.
Daily--- Arcane
Standard Action--- Ranged 10
Target: One creature.
Attack: Intelligence vs. Fortitude.
Hit: 2d6 + Intelligence modifier damage, and target is slowed until the end of the encounter or until it spends a healing surge.
Miss: Half damage, and the target is not slowed.
Effect: The target has a -2 on attacks and defenses (save ends).

 

[Paultimatum]

I'm not an expert on balancing powers, but ill try.
Thunderous Blow--- Cleric Attack 23
I've never played at epic levels, so I have no clue.
Bite Spirit--- Wizard Attack 1
I like the idea, although dazed may be too powerful as an at will as it grants combat advantage.
Bonebreak--- Wizard Attack 9
Does this mean that they are slowed until they spend a healing surge by some other means, or that they can use a healing surge to cure this effect? If it has to be spent by some other effect it might be overpowered, since most monsters have no ways of spending healing surges. If the second way, it might even be underpowered because monsters have a healing surge per tier and no other use for them, so the slowed condition is bound to be cured on the next turn and with no real cost. I like the idea of healing surge ends effects though, and the power looks neat.

 

[Mustrum_Ridcully]

Thunderous Blow--- Cleric Attack 23
You bring your weapon down on your enemy, and a peal of thunder echoes from the blow, blasting your foe from its feet.
Encounter--- Divine, Thunder, Weapon
Standard Action--- Melee weapon
Target: One creature.
Attack: Strength vs. AC.
Hit: 2 [W] + Strength modifier thunder damage, and the target is knocked prone.
Miss: Half damage.
Effect: The target is deafened until the end of its next turn.

Deafened is not a particular common - or useful - effect. Knocked Prone is good, though. The Fighter has a 1st level power that deals 1W damage and knocks prone. (No other effects.) I initially thought 2W might be too little, but compared with other 23rd level powers and powers below that level, it seems okay.

Bite Spirit--- Wizard Attack 1
You attack your foe’s spirit, leaving them wracked with agony.
At Will--- Arcane, Necrotic
Standard Action--- Ranged 8
Target: One creature.
Attack: Intelligence vs. Fortitude.
Hit: 1d6 + Intelligence modifier necrotic damage, and the target is dazed until the end of your next turn. Increase damage to 2d6 + Intelligence modifier at 21st level.

Dazed is too strong for an At-Will power. As will be weakened, I suppose. I think the effect of Illusory Ambush (-2 to attacks) might be the closest you can get. Even granting Combat Advantage seems to be too much (compare it to the Clerics Lance of Faith ability that merely grants a +2 power bonus to attacks.

I am not sure if an attack on a creatures spirit shouldn't be psychic instead of necrotic, but that might depend on as what you see "spirit" for a creature. Remembering the fluff on the Shadowfell and the Open Grave excerpts, "Soul" might be the better term.

Bonebreak--- Wizard Attack 9
You point your implement at the enemy, and it shrieks in pain as one of its bones cracks and breaks.
Daily--- Arcane
Standard Action--- Ranged 10
Target: One creature.
Attack: Intelligence vs. Fortitude.
Hit: 2d6 + Intelligence modifier damage, and target is slowed until the end of the encounter or until it spends a healing surge.
Miss: Half damage, and the target is not slowed.
Effect: The target has a -2 on attacks and defenses (save ends).

[/QUOTE]
As the poster before me already said, the mechanic of being slowed until it spends a healing surge is a little wonky. You could say that the target only is allowed to make a save against the slowed condition if it takes damage (maybe 5 or 10?) instead. (Which would make it a nice controller power, I think - forcing the target to choose between taking more hurt or moving as it likes...)