For me Earwa is an objectively expressed, collective, subjective imposition of consciousness which the Inchoroi aim to subvert somehow understanding that Earwa can be key to their salvation. Kellhus may be doing the same thing, whether in pursuit of his original Dunyain goals, his declared Aspect Emperor goals, or some motive unknown to the reader.
I think Kellhus went mad on the circumfix - up until that point he was becoming increasingly emotionally responsive and I think the circumfix tipped him over the edge. I think a Dunyain with emotional response is insane by Dunyain standards already but maybe not by our standards.