I have in the last 2 months adopted the Drakh as my secondary race. And man, if you take the GEG at face value, are you missing the point. It's NASTY.
The GEG gives you an option that many other fleets don't have -- drive right into the middle of a formation. Usually, if you go there, the secondary batteries will kill you dead, and the primary beams will kill something else. It's just about as close to suicide as it gets. Drakh Raiders go in, however, where angels fear to tread. The raider (especially the LR) can just waltz in, Dodge a whole mess of stuff, and, as long as the secondary guns aren't very big (7-8 dice is Light pulse, 6 dice twin-linked weak is OK), you'll come out standing tall. No other skirmish ship can even consider such a thing!
Flanking oftentimes just gives your opponent another set of guns to use during his fire step. The GEG, however, renders most of those secondary guns moot. If you're in love with Napoleonic flanking in space, this is the system that makes it work.
As to the Carrier and Mothership and the GEG not being enough -- it isn't. And it's not supposed to. Consider the mass of Raiders you got (SFoS) for those ships. In order to make sense fleet point sense, the Carrier and Mothership need to be dubious choices over the appropriate number of Raiders bought outright. Frequently, the value of the ship is purely in the raiders. To balance this, you need to have the value of the Carrier and/or Mothership be zero -- high liability, high reward. If the GEG got any stronger, they would not fit this profile.
As to the GEG 3 Cruiser -- it's a monster, and it's supposed to be, espeically given you've got a Hull 5 Battle-level main combat ship; that's very rare. Outside of the Minbari, they don't exist. Of course, their beam arrays are awe-inspiring (8 total dice!!). These brutes jump into the midde of a force, past beam arrays, and just go apes**t.
And the GEG makes all this nastiness possible. If there's three things I'd criticize, they would be
1). The Light Raider is just too durable
2). That Scout has WAY too many guns on it! Spooky!
3). The Fast Destroyer is downright pointless. 3 45's and 2" of move and I change my mind -- you'd then have to remove some of it s guns to balance it.