I am struggling to, A: get curved surfaces to have a smooth rate of change, when looking at the curvature combs,

and B: get separate surfaces to flow from edge to edge.

You are free to examine my chosen features, but to save you some time, here are some of my thoughts/findings:

All sketch curves used for 3d faces are beziers.

I am able to get tangency on all surfaces that should have it, just not flow.

Yes, I did a very poor job of constraining the body profile sketch. I will redo it eventually. The rear headstock sketch is unconstrained for the time being.

The split feature that cuts out the treble side horn breaks when changes are made to the body profile sketch. (non manifold edge?)

I have tried boundary surface, loft, and fill on the headstock and heel joints, and only fill works. Seemingly because the guide edges join the loft profile at an angle.

Multiple connected bezier curves are needed to create the body profile. When extruded, they create these unnecessary (?) edges where they join:

That's about all I can think of. If you read to the end, here's a cool picture of the bridge I plan on making for this.

I appreciate any help or comments! Thanks.