Wow, never connected Seswatha's heart with the Daimos, but thinking about it, it makes perfect sense. Maybe Kellhus is controlling Akka's dreams through the Daimos?
Need to re-read KOMH, don't remember that aspect of it you mentioned.
Edit: I wouldn't label language as an intrinsic part of sorcery at all, just one of the methods one can use. The correlation between meaning and language makes it very useful and teachable, since it is intellect-dependent.