Firstly the electric shuttles are very overpowered. They are able to destroy a fleet in a few seconds and no amount of defenses can halt them, as they inflict the same damage to all units in range. They need a significant decrease in damage against certain ships, so that they are still effective against fleets on the whole but can't be used to instantly negate a vast incoming fleet.
Secondly, the starfleet commander can get so overpowered that there is no way of attacking a certain planet. This is a prime example:
If we even attacked that planet the resulting flood of starships would crush all of our combined ships and turrets. A nuke isn't practical either, so I don't see the point of this AI type.
Thirdly, the beam starship is like a tank. I don't think dreadnoughts have a bonus against them, they just cripple their engines. So that needs some attention.