A ready check for every dialogue? That would get annoying pretty quickly. The game already tells you that's "there's an interesting conversation nearby" for key story elements. If it's something you want your co-op players to hear/see, speak up and let them listen in before continuing.
The roll-off gives me flashbacks to the DOS rock, paper, scissors system. A roll is a slightly different mechanic, but gives the same result. The game already has the option for co-op players to suggest lines, without taking over the conversation.
In terms of role-playing, I don't really agree with the 'face' mechanic of always sending up your most charismatic or persuasive person. If you fail a roll because your stumbled into a conversation, so be it. I don't want to win every roll every time, otherwise what's the point?
I didn't really know about the "interesting conversation bit" myself, me and my friends usually stick close together anyways. And yeah, the ready check part of it was more of a holdover from how SWTOR handles it. I still think it would be good to have something like it- like Icelyn said, it can be pretty easy to miss the start of a conversation even when you're on the ball about it- but if that part's not needed, it doesn't really need to be there anyways.
I actually kind of liked the idea of the DOS rock paper scissors thing. The difference between that and this is that it would be a lot faster and less intrusive, though. Just click an option and your roll is made behind-the-scenes, and the result just pops up so everyone can see it. And yeah, you can already suggest your answer, but that's kind of my point? All you can do is suggest, and at least for me and my friends personally, we just kind of stopped doing it after a while, because there's not much point. It's more interesting to be actively engaging in the conversation than just suggesting a line that my friend probably isn't gonna pick anyways, because we have two different character types we're playing. I don't really see the harm in letting each player co-opt the scene every now and then- just like in a real D&D group, everyone should be able to spontaneously have the chance to shine and chime in, instead of just having one person front an entire scene.
As far as the face mechanic, yeah, that's a personal taste thing. Personally I find it kind of unfair when I'm ambushed with a conversation mid-combat or mid-exploration, and I'm locked as a character that can't talk for anything, and the person that actually is a good talker is just deciding to be stoically silent for some reason. Again, just like a real D&D group, everyone should have the chance to chime in- as well as the chance to decide to stay quiet and let the talker talk, or the rogue pick the lock, or whatever's going on in the scene.
