Ok I am going to give you my quick thoughts on some more of your creatures. I don't think I will comment on the AC or NADs or it might drive me insane. 
Cranium Rat Swarm
I really like the idea behind this creature.
I would be careful with the Mind Blast power, when using multiple swarms I predict that you will be able to chain-stun at least some of your PCs with it. Couple that with the general nastiness of swarms in the first place and this creature might be a lot more dangerous than it at first appears.
Cult of the Dragon Necromancer
This creature would be better as an elite or at least a Leader, as a standard creature you must realise that you could have 5 of these as a standard encounter.
With the sheer magnitude of damage this guy can put out I would be more inclined to make him an artillery creature rather than a controller, he just doesn't really do any controlling.
The Dracoliches Revealed is a prime example of something that seems cool on paper but can go horribly wrong in practice. 3d10+4 damage of so many types that it is effectively unresistable is just too high for a standard (and non leader) creature, then when you are applying that damage to a 5x5 area it has the potencial to destroy any appropriate level party. Now my guess is that you would only consider using one of these guys in an encounter, but as a standard creature it is at least possible that you could have 5 of them which would be a TPK. Even two would stand a very good chance of killing a few PCs especially if they waited until at least one PC was bloodied before unleashing the power.
At least if you made the creature a leader it would inform people that they could only use one of them, and would allow you access to the higher damage expression attacks.
The Dracoliches Skull power is nice, I think it should probably include a minor action to sustain it.
Duergar Mecenary
I like the variation with Deep Impact but this should probably either be a recharge 4 power or do less damage, 1d8+4 maybe. Otherwise my prediction is that they will pretty much always use it over there vs. AC attack. It is also going to really punish defenders, and a soldier punishing a defender seems a little unusual.
Psychic Weapon again could cause problems when you actually get into combat with these guys. You are going to suddenly realise that you have three of these guys next to a level 6 PC and can unleash 3x 3d8+4 damage on them (with an excellent chance of hitting) that in a worst case scenario is 84 damage, a level 6 PC might have around 55 HPs, if 3 of them have charged him the previous round he might have about 40HPs if he hasn't been healed.
This is a lesson I learned a long time ago, high damage encounter powers are very dangerous on standard creatures. They are even worse on soldiers who have a higher AC and HPs.
Expand again is a great idea for a power. I would probably recommend reducing the creatures AC and attack bonus in its new form though. Remember that this is a soldier who are meant to have high AC and HPs but low damage. This power turns him into high AC, high HPs and high damage. I would give him a -4 to AC and a -2 to hit, the easiest way would be to split some of his attacks between cannot use while bloodied, and only while bloodied so you can change the attack and damage bonuses in a way that will make the creature easier to run.
I hope these comments are useful, I am trying to explain my criticisms in a constructive way, of course you are free to disagree.
Anyway only 26 more creatures to go.
Cranium Rat Swarm
I really like the idea behind this creature.
I would be careful with the Mind Blast power, when using multiple swarms I predict that you will be able to chain-stun at least some of your PCs with it. Couple that with the general nastiness of swarms in the first place and this creature might be a lot more dangerous than it at first appears.
Cult of the Dragon Necromancer
This creature would be better as an elite or at least a Leader, as a standard creature you must realise that you could have 5 of these as a standard encounter.
With the sheer magnitude of damage this guy can put out I would be more inclined to make him an artillery creature rather than a controller, he just doesn't really do any controlling.
The Dracoliches Revealed is a prime example of something that seems cool on paper but can go horribly wrong in practice. 3d10+4 damage of so many types that it is effectively unresistable is just too high for a standard (and non leader) creature, then when you are applying that damage to a 5x5 area it has the potencial to destroy any appropriate level party. Now my guess is that you would only consider using one of these guys in an encounter, but as a standard creature it is at least possible that you could have 5 of them which would be a TPK. Even two would stand a very good chance of killing a few PCs especially if they waited until at least one PC was bloodied before unleashing the power.
At least if you made the creature a leader it would inform people that they could only use one of them, and would allow you access to the higher damage expression attacks.
The Dracoliches Skull power is nice, I think it should probably include a minor action to sustain it.
Duergar Mecenary
I like the variation with Deep Impact but this should probably either be a recharge 4 power or do less damage, 1d8+4 maybe. Otherwise my prediction is that they will pretty much always use it over there vs. AC attack. It is also going to really punish defenders, and a soldier punishing a defender seems a little unusual.
Psychic Weapon again could cause problems when you actually get into combat with these guys. You are going to suddenly realise that you have three of these guys next to a level 6 PC and can unleash 3x 3d8+4 damage on them (with an excellent chance of hitting) that in a worst case scenario is 84 damage, a level 6 PC might have around 55 HPs, if 3 of them have charged him the previous round he might have about 40HPs if he hasn't been healed.
This is a lesson I learned a long time ago, high damage encounter powers are very dangerous on standard creatures. They are even worse on soldiers who have a higher AC and HPs.
Expand again is a great idea for a power. I would probably recommend reducing the creatures AC and attack bonus in its new form though. Remember that this is a soldier who are meant to have high AC and HPs but low damage. This power turns him into high AC, high HPs and high damage. I would give him a -4 to AC and a -2 to hit, the easiest way would be to split some of his attacks between cannot use while bloodied, and only while bloodied so you can change the attack and damage bonuses in a way that will make the creature easier to run.
I hope these comments are useful, I am trying to explain my criticisms in a constructive way, of course you are free to disagree.
Anyway only 26 more creatures to go.
