I could not think of a good way to describe it a snappy way for the title but i'm referring to how people can like or dislike you based on how you respond to them. If you shoot them and some other things also effect it.

It never seemed to matter much at all but maybe it was just subtle. Does it effect the story at all?

I believe it only affects the ending.

Which is a bummer, as I would have wanted it to affect more than that, even if it was something like the characters' capabilities in combat. Makes me think other squad based games would benefit from a Persona-like "Social Link" system.

I believe it only affects the ending.

Which is a bummer, as I would have wanted it to affect more than that, even if it was something like the characters' capabilities in combat. Makes me think other squad based games would benefit from a Persona-like "Social Link" system.

That is a bummer. How many endings are there? I would like to read a breakdown on how it assigns those endings.

Edit: Seems like a waste of a potential good mechanic and story device. So I guess that means that the second half of the game can only be played with Faye and Cain. I figured that may have changed depending on relationships with the characters.

I can't confirm this, but I believe it also affects the likeliness of your teammates to follow your commands, though to be fair, that's not very useful anyway. 
 
As far as its effect on the ending, there aren't really "multiple endings" - it's more like the way the ending plays out is varied a bit depending on trust levels. With that in mind, it can affect who lives and dies for a couple of characters, but the general ending is the same. I think where your trust level is with Faye influences a scene at the end of Act 4 (or Chapter 4; I forget how the game labels the levels), but I don't think there's any other impact besides the end of the game. I'm pretty sure the lone FAQ/Walkthrough on GameFAQs covers how the ending exactly is affected by trust levels if you feel like reading about it.
 
Edit: Oh, and yes, that section with Faye and Cain is always played with Faye and Cain.

@ImmortalSaiyan: The endings are fairly different in that some characters can die if you don't have your friendship with them up high enough. And the above poster is right. It effects how likely they are to follow your orders in combat. It doesn't alter the story up to the end though as far as I know.

@ImmortalSaiyan said:

So I guess that means that the second half of the game can only be played with Faye and Cain. I figured that may have changed depending on relationships with the characters.

This was extremely disappointing for me to figure out when I got deeply enough into the game. It would have been amazing if, at the point where the squad is forced to split up, if the story would sway depending on the status of the player's relationships. But nah, the romance with Faye and all of that is obligatory.

Still, the mechanic holds promise.

@FluxWaveZ said:

@ImmortalSaiyan said:

So I guess that means that the second half of the game can only be played with Faye and Cain. I figured that may have changed depending on relationships with the characters.

This was extremely disappointing for me to figure out when I got deeply enough into the game. It would have been amazing if, at the point where the squad is forced to split up, if the story would sway depending on the status of the player's relationships. But nah, the romance with Faye and all of that is obligatory.

Still, the mechanic holds promise.

So you can be a total jerk to Faye and the romance still happens? I though it felt forced to me and I was nice to her.

@ImmortalSaiyan said:

So you can be a total jerk to Faye and the romance still happens? I though it felt forced to me and I was nice to her.

From my understanding, yes. You could shoot her as much as you wanted in the field, but that romance scene and everything after that involving Dan and Faye would remain the same.

It affects the ending, yes. But it also affects your followers probability of following commands.

Say I had Rachel at 1 bar and Faye at 4, and I tell them to open fire.

Rachel tells me to "go eat a dick" and kills everything anyway, while Faye says "Sure thing, Bro!" and misses all her shots.

So it does have a bearing on gameplay, albeit a very slight one.

@FluxWaveZ said:

@ImmortalSaiyan said:

So you can be a total jerk to Faye and the romance still happens? I though it felt forced to me and I was nice to her.

From my understanding, yes. You could shoot her as much as you wanted in the field, but that romance scene and everything after that involving Dan and Faye would remain the same.

Brilliant. Why even bother with a loyalty type system if it so trivial. I wonder how people who treated Faye poorly about that and the ending. She probably seemed crazy to them. I found her the only character I cared about in the slightest.

Interesting system, not utilized very well in the game, unfortunately.

Seems only your relationship with 1 or possibly 2 characters even comes in to play in the end. (other than a best ending, which I believe requires full trust with everybody)