Fusing various breps together

I believe the blobs in the GH UI are some sort of metaballs.
For equivalent with meshes in 3d you could look at Dendro or one of the other isosurface plugins (search this forum for isosurface)

For physical shrink wrapping you could look at this:

For SubDs you could try the new Fuse component in GH (now found under the SubD tab in the latest v7 beta)