Some thoughts:

Zergling:

Should the bonus atk and damage only be against the bloodied foe?

Does the Burrow ability allow the zergling to move squares underground (ie. from square A3 to square F5) or only to disappear into the ground? It's a while since I played Starcraft but IIRC it's the latter. Perhaps zerglings would be better built as lurkers?

The Erupt moves should say "if the Zergling erupts adjacent to an enemy". The word "near" is just confusing. You also need to specify whether the attack is a separate action or whether it's part of the Erupt (effectively allowing the Zergling to attack as a move action in the right circumstances).

Hydralisk:

Area Burst 3 is a 7x7 square. That seems awfully large and I don't remember the Starcraft hydralisk having an equivalent ability.