Keltham will seem calmer, maybe even a little friendlier, while he's wandering around outside carefully not inflicting his emotions on other people.
Keltham will furthermore note to himself internally - especially now that he's got the higher-powered Nondetection layered over his amulet - that the real him seems to be calmer, now that he's trying to give the emotional impression of a calm person. Being outwardly upset and wounded is hazardous to your insides, apparently, even when the upset and wounding are drawing on something real; there may be more wisdom than he understood at first, in dath ilan's rule of not showing off your injuries.
As for Sothis, yes, Keltham has grasped the difference between rich people who can afford Endure Elements and non-rich people who can't, since it's so visually distinct. Keltham's not going to try a nonrich woman until he has experience talking to people that Osirian considers full human beings, though.
Any non-busy merchants selling something cheap enough that Keltham could trivially buy it, and the profit on the item would be enough to repay them for some idle chat while Keltham shopped?