You've again touched on my point. I would LOVE for the origin characters to give me good reasons for us to adventure together. Thus far, SH does, but this is negated if she lies and people suspect her of being a backstabbing Sharran. I'd take my chances without her if I wasn't honestly metagaming. At the very least, I'd travel with her only to the grove and then BYE.
Astarion is the same. Gale... Yeah. Okay. I'd kinda feel more comfortable, but I still expect him to stab me in the back at any moment. Same with Wyll and Lae.
In short. I would LOVE the opportunity to question SH, and find out she's a Sharran right up front - if I succeed in Religion and/or Insight checks to see through her lies. But then have her say something like how we need each other. Can't I look past my prejudices. There's something weird going on. We're connected. Let's try to work together at least for now until we figure out what's happening. Basically, ha e her and/or others give me solid reasons to put up with them and at least work with them for necessity sake.
^This. It truly would be shocking to me if none of this were possible in the final version of the game.