I see many gamers that like the idea of better written games, however I don't think that this necessarily translates into the need for long conversations (ie. like in Planescape Torment). I think that simple gestures and behavior (and visual characterisation). For example in Zelda: A link to the past, when you rescue the princess at the start she follows you, so I assumed that you had to protect her from the soldiers and cleared out the rooms ahead of her. Whereas in Earthbound on the SNES, your neighbour wants you to find his little brother at the start, and he says "you go on ahead and I'll follow", so he is likewise following you. But it is obvious that he is being a coward and he hides behind your characters in battle.

All these things you describe, Ketcheval, are determined primarily in the character design. I have a tool you can use in my web at this link:

Clicky

This template was originally designed for designing theatrical characters, however, is a good guide for developing fully fleshed out, believeable characters, so you know them behaviorially, so to speak, to write their interactions and exchanges with the player not only more efficiently, but also more believably and flexibly.

Adventuredesign