How to fill a closed curve with Sculpting or Smoothing etc?..&turn curve into Mask?

Support Modeling
1

Hello BlenderArtists,
i hope you might please show,.

  1. how to (flood)fill a closed curve with Sculpting or Smoothing etc.?,
  2. how to close a Bezier curve in Sculpt Mode?
  3. how to use Craig Jones, Awesome! Artist Paint Tools\Panel > Canvas Mask Tools(Make Vector Contour\To Mesh Mask…) in Sculpt Mode?

Some sculpting programs can apply sculpting along a curve but applying sculpts within closed curves would be great in Blender. But if its unable please suggest any capable software if known.
Really appreciate any advise,
J