Role of dialogue

[Golem]

I often get several options in dialogue. Some give information, while others have an impact on the character I'm talking with. Do you have a sense of what impact you'll have? How wide is the range of effects?

For instance, with Gizmo,

[Yourself]

I've generally found that past the first set it's pretty clear which dialogue options are going to lead to generic backstory and which are going to lead to job offers/leads. Considering I'm playing to avoid talk quests and go straight for the action, this makes sense: my character doesn't get into conversations over his head. I've also found that setting is important to how incendiary snark is going to be: Gizmo the greasy businessman doesn't jump straight to violence at being insulted, but keep goading him and he will. On the other hand, run into the gang hideout and say something snidey and you'll be under attack in one click.

On an unrelated note regarding Gizmo.

[Yourself]

It might be useful to break down "dialogue" by it's functional purpose. If I were to take a stab at defining mutually exclusive categories for the rewards provided by engaging in dialogue, I'd say:

1.) Story: responses that provide unique characterization or background information about the setting and culture
2.) Circumstantial guidance: responses that help narrow down where to find a person, place, or job - e.g. being told that Vault 15 might have a water chip or that Arradesh is looking for help
3.) Interactive guidance: responses that help predict outcomes of certain actions, like being told that the gang in Junktown (can't remember their name) doesn't like outsiders, or that sending Water Merchants might reveal Vault 13
4.) Objective progress: responses that progress the state of a quest - the simplest being accepting a job or reporting it complete
5.) Trade access: I haven't yet run into a character I had to talk into bartering, but I have certainly lost access to it via dialogue choices
6.) External behavior: responses that cause an NPC to do something outside of dialogue, like Ian joining the party or Gizmo attacking

This (or a better classification system) might help in discerning how dialogue is useful to different players depending on play style, how it's dispersed through the game/level structure, and how these ideas are thereby coupled.

[Golem]

I fought Gizmo that way too, but nobody got mad about it. I wonder what we did differently.

It's interesting to see the number of reasons a player might have to pursue dialogue. Because you're going on purpose, it's based off of what a hypothetical player might expect.

So far as the game itself goes, either the dialogue triggers something to happen or it doesn't. It sounds like you find it easy to link your dialogue option to the resulting NPC reaction and subsequent trigger.