Why is the Flesh Golem so crunchy?
Maybe add a lightning damage aura to one of the soldiers that does a token 5 points or so damage.
I actually quite like the Flesh Golem. But the first thing that springs to my mind is a horde of minions with special prods that have reach and do 1 lightning damage. Imagine the carnage when the Flesh Golem is making 4+ free basic attacks each turn

. Even worse, some sort of ranged low damage lightning attack!
I agree that the Golem is going to get cut to ribbons, but it is going to dish out a reasonable amount of damage before it dies, and it does get a +2 bonus to attack rolls when bloodied. I think it will be threatening enough.
The Vampire on the otherhand I am not so much a fan of, I think if it was an elite I might like it more. I do like that it is designed to be able to escape a battle, but really this is more appropriate for "named baddies" or in other words elites. As a standard level creature I think it would be a little annoying to fight (and not really in a good way).
I really like Cloud of Bats but I think I would prefer it as a recharge 56 move action with a
Sustain Standard action with the power not being able to recharge while it was active.
I don't think Dominating Gaze should get a recharge at all for a standard creature, really it should be an encounter power. I know it is doing no damage itself, but it has a bonus +2 to hit and against will it will easily find an easy target, which will probably be a groups damage dealer. The prospect of multiple Vampires spamming this attack does not conjure up the image of an enjoyable encounter at level 12 in my mind. Again if teh Vampire was an elite this would be a lot more reasonable.