Advising against KS because of static issues? That is simply nonsense. Your concerns regarding channelling are also unnecessary. You urgently need expertise.
Advising against KS because of statics? That's simply nonsense. Your concerns about chasing are also unnecessary. You desperately need expertise.
KS as interior walls because of the weight since the living room is completely spanned. It may be that 17 is enough, but a friend who is an architect advised against it. I will rather clarify that with the construction company regarding the thickness.