🚀 go-pugleaf

I need to make rather specialised drawings (for the molecular biologists
under you: RNA secundary structure models). Rumour has it that it is 
possible to write extensions to Artworks. I would like to know whether this is 
indeed possible, how it is done, how difficult (or easy) it is, and what the
possibilities are. I need the possibility to create the drawing on basis of a 
data file.
I think I would also need following features:
      dynamic grouping: The drawings are kind of tree like: when the user 
         selects a branch (for instanse to rotate it), all depending branches 
         should be selected and rotated together with the parent.
      Text following a line, but the letters allways stay horizontal when 
         rotated (yes somewhat like rotating a group of characters in 
         RISC OS 2 Draw)
I would like to know whether it is possible to implement these things 
in/together with Artworks, well, for a non official developer that is.

Any information will be greatly appreciated,

Peter