Overall I have no problems with your post, frankly I'm just happy that someone gave the thread a sorely needed kick. And yeah, Carcaroth reacted pretty much as he would have if someone he had never seen before in his life came forth and claimed to be his son in such a situation. If I had to point something out, it's that I reckon Carcaroth would seem too young to be Tarok's father, seeing as Tarok has the appearance of a thirteen year old boy and Carcaroth is in his mid-twenties. It's not a completely unbelievable premise, but a pretty shaky one.
I think their "relationship" would be more plausible if Tarok had claimed that Carcaroth was his elder brother, rather than his father. That would keep them "blood relatives" while also taking into account their age relative to each other.