The "flagship" rule at the endurance still states that an additional turret can be taken for +10 points (should be +5)
Mars: I think the mars should be in. Simply because you'll see a lot of Carrier BC's in bakka, as it is their only source of AC. And I prefer a fleet with mixed ship classes instead of only one type. A fleet with one mars and one dominion looks nicer than one with two dominion.
At all it is no big difference, but I don't see a reason in forbidding a ship class as long as both clases are almost equal in worth and performance.
Same question for the overlord: is there any reason why it is not included? The fluff speaks that it is hard to build an only a limited number served in segmentum obscuras, but that doesn't mean that other forgeworlds in other segmentae have the same problem

It is surly not an overpowered design and the 60cm guns as well as the 3rd turret option show that it is a ship in the "spirit" of Bakka.
Btw.: is there any chance that we can see a 1:1 BC ratio as mentioned some pages ago? IMO that would fit the big gun theme well...
Dauntless: here I'm not sure. I love the dauntless. It is by far the best navy light cruiser class. But this is the problem: You won't see much Siluras under the current rules, but you won't see any of them if you can include a dauntless which is only 10 points more expensive and far superior.
What Bakka IMO misses is a unique basic cruiser that “fits†the philosophy. Perhaps something like a Dominator but with torps instead of a Nova and a 3rd turret.