Yeah, so far so good. I think you hit on what I would rather happen if Sanchez is not going to be the guy. I would rather have Lynch in there. I know the risk (and it is significant) that you may destroy his confidence if he is shoved in there too soon. That is significant and it is something to consider.
Like you said though, he is very protected by the great defense. He essentially would not be asked to score 30 points per game. He has the skill to run that stretch run since he has the skill to run keepers and bootlegs.
I just do not think it is in the plans. To me Siemian makes it confusing. Like someone said, you go with the best QB. Well, I like Siemian, but I have not seen anything that overwhelming about him.
IMO, unless he is overwhelming, then it needs to be either Sanchez or Lynch.