Why does the Wracu high rate of mutation rule out selective breeding? Its a basic tool of managing traits and the high rate of mutation means you're going to have a bunch that don't function very well or can't live because they're messed up internally. Sky high hatching mortality is likely and probably keeps their numbers low. Wracu are long lived so its quite possible their have only been a few generations with which to direct their development.
This just isn't how selective breeding works. It takes thousands of generations to get any meaningful separation of species/traits. When dealing with something that has any kind of generation time measured in years, let alone decades, this is just not possible. It would take millions, 10s of millions, of years to get what you have with the wracu. Since they were created on Earwa, its just not possible.
Granted, there's a ton of nonsensical biology that goes on in Earwa. We can simply say that "alien biology works differently", and therefore literally anything is possible. I find this unsatisfying, but acceptable. Magical Inchoroi "technology" coupled with infinitely "alien" biology, and a case can be made for anything. But if we're assuming any kind of IRL biology, selective breeding isn't possible.
I've seen zero evidence that Skin Spies are more intelligent than Wracu. Skin Spies are trained to mimic men and infiltrate, which is something Wracu obviously can't do but they certainly comprehend and use language.
I disagree completely, but we're reading the same stuff so there's nothing else to say for this one. IMO, complex social behaviors indicate an extraordinary level of intelligence, well beyond anything we see of the wracu - which are closer to bashrag/sranc though maybe a bit smarter.
Did they find Wutteat in space? The lines given suggested to me that he had been created in the Ark while it was in space.
Its vague, but the general consensus is Wutteat was found in space. I believe the books are more clear that Wutteat is the template that the Earwa inchoroi used to create the Wracu.
As for the No-God controlling the Wracu, the writings suggest to me willing submission not control. The No-God does not shout through Wracu throats. They behave like vassals, not puppets.
That's not how I remember it, but its been a long time.
Souls in Earwa aren't the product of pure intelligence, but they do seem to require a near human level of intelligence because souls clearly require a significant level of self awareness.
I agree with H here, intelligence and souls seem to be unrelated imo. If random animals can have souls, then its not an intelligence thing.
The Wracu seem to possess this, although that might not be true. Unlike Skin Spies we are not privy to their thoughts.
We have few intereaction with Wracu, especially disregarding Wutteat, but imo they show very limited awareness of any kind. Something closer to a sranc than anything else.
The other Weapon Races are dominated by their instincts and seem to lack both self awareness and ability to process contradictions.
Being dominated by instincts doesn't preclude the existence of a soul, nor does it guarantee it. Again, random animals can have souls.
Skin-spies must be extremely self aware to do what they do. As for the rest, probably not, and I include Wracu in that.
Sranc aren't as senseless as you seem to think though. For example, they have language, culture, complex social structures. They also are used as Elju for Nonmen, which indicates a huge capacity for not just memory and recall, but also communication.
All this to say, Wracu very much fit into the standard Weapon Race role. They aren't exceptional, other than their physical variation. I see no significant reasons for why they should have special rules.