I noticed that you didn’t tackle the mythological roots of the character. Any specific reason why not?
Only, we all know that ‘Robin’, as in Robin Goodfellow, is a by-name for the Puck or Hobgoblin, a mischievous sprite who haunted forests and played tricks on travellers. The figure of Robin Hood shared many of Pucks’ characteristics; mischief, mockery of the over-proud, help for the humble. Also the ability to vanish into the woods when pursued.
The fact that our image of Robin includes wearing green further associates him with old forest deities such as Jack-in-the-Green. His close association with oak trees links him with Druidism and to the Oak or Summer King of certain Wiccan traditions.
I’m not saying that the character is wholly supernatural or mythical. Just suggesting that some of these mythical themes might have become attached to a composite figure created by balladeers.