1)  I'm not particularly fond of the sudden appearance of previously unknown grown offspring.  Namor is too much the prince to have hidden an heir.  Ensuring his successor and training him, would be the best thing for Atlantis.  Nor do I see him abandoning his child and allowing someone else to raise him, especially since he himself grew up without a father.  And then there's this nameless woman, the mother, who Namor claimed to have loved.  When exactly was that supposed to have happened (like between his two wives?), and why haven't we heard of her before this?  Namor isn't shy about talking about the important women in his life, and she's never been mentioned.  Kamar would have worked fine as yet another ambitious cousin ... or how about Byrrah's kid?  There was no reason for him to be Namor's son.

and Namor's plans for a fifth column, it would have been worth it.  But no.  Instead of Atlanteans among us, we got Secret Invasion. :(