This post is really friggen good. I love how you've explained it all out. Really, really hoping they do the third route and yes, we know that Swen and Larian genuinely care about the fans and our interests.
That brings the point of Zariel hanging on Karlach's tail; it wouldn't be that weird given that they'd have meddled with her toys and champion/greatest asset, but also because genuinely everyone has a god after them or bound to them by endgame. Lae'zel has Vlaakith, Shadowheart has Shar, Gale has Mystra, Wyll may cut his ties with Mizora who no, isn't a goddess but still a connection to the hells, and Astarion has his own complexes.
Not all of these are negative but in my main playthrough for instance, all main Origin ladies would have a really powerful goddess after them. So that evens out LOL
