You should be good, you start out from Andoran, land of freedom and honey, so unless you're playing a racist douche bag for some reason you should be cool with a couple of weirdos. :-)
Also remember, you're all the best and brightest recruited, so if the venture company is cool with tieflings then so should you.
Have fun!
Depends on how you define your eldritch scoundrel, RP wise. I could imagine a classic rogue to be used to shady comrades - he will be skeptical and quick to make puns, but also look what opportunities this alliance might offer.
Current Cheliax looks down on tieflings - the diabolic government thinks humans should use Hell, not be used by it. So tieflings might evoke some pity from Andorans. And, who knows, some tieflings might make natural (though dangerous) allies for Andoran, since they want to pay Cheliax back what they had to endure...