It should be possible to access basic properties:

• create new layers.
• delete layers
• name layers
• change layer state
  • visibility
  • alpha inheritance
  • lock
  • onionskinning
  • layerstyles????
  • alpha lock
  • passthrough(for groups)
  • layer blending mode
  • opacity
• create clone layers of node.
• create masks
  • filter?
  • transparency? Via split alpha?
  • transform masks?

For that matter, animation api?

Filtering:

• Filter by name
• filter by color label
• filter by type
• filter by layer state?

Merge control:

• merge all
• merge group node
• merge masks into layer
• merge array of nodes.