Michael:

I just wanted to say, clicking and dragging anywhere on a curve to modify it has been in Inkscape for a few releases now... ;)

Maybe you can steal a few of their other ideas as well.... <:)

Pattern along path:
Mmm, imagine this applied to arrays in Moi.
http://www.inkscape.org/screenshots/gallery/inkscape-0.45-patternalongpath.png

Thicken and thin closed curves, and Guide Paths
http://www.inkscape.org/screenshots/gallery/inkscape-0.46-engraving2.png
http://www.inkscape.org/screenshots/gallery/inkscape-0.46-engraving1.png

Drag the Curve to edit it:
http://www.inkscape.org/screenshots/gallery/inkscape-0.43-nodeedit.png

Node Sculpting: ( Think Uber Curve Drag )
http://www.inkscape.org/screenshots/gallery/inkscape-0.44-nodesculpting.png