I think that Hermes was probably pretty good at hiding his issues up until Meteion entered the picture which just so happened to coincide with the point of time in which Hythlodaeus and Emet-Selch came to visit Elpis. Which also, conveniently, coincided with Venat's presence and the arrival of the player character.

As for Emet-Selch, it was always clear to me that he cared more than he let on. I don't think, for example, that it was a coincidence that he sought to empower the very people who suffered the most amongst the Sundered as a consequence of the Sundering. Namely the Garleans. It makes me wonder what he would have done had his son not died in the way that he did.