I Got Soul
The Augury is pretty clear: "No." It's also pretty clear that your Augury comes from Zelba's people, which is a little scary.
You confer with Grettin and Shettin. "Hmm." They throw some bones. "It looks like Zelba's got your nuts in a vice, so to speak. If you don't go after Master Vrill and his daughter, then, sigh, rebuild the temple, she'll just snuff you out. Grisbane can't do much about that. I mean, you walked into her home. She gets your soul, it's sort of how it works."
"It's not hopeless though. You probably should fulfill your part of the bargain. When a goddess commands you directly to do something, you should do that something. Makes sense to us. Once it's through, come on back and we'll Atone you, that should do the trick. Of course, Grisbane might have his own demands for the Atonement, but you can worry about that at the proper time."
...
While you're training, you can deliver your broadsword and the magic crystal to the famous blacksmith Fallsworth in Durth. He'll forge your sword good for 400 gp, and it'll be done by the time you finish training. That'll put it up to +2 I think, not bad.