Category to Tag - Tag to category

I would like the feature to select one of my categories and have this turned into a tag.

What do i mean

My category is called 'Smurfs'

• select a category
  
• select convert to tag
  

What happens now

• all items in the Smurfs category have the tag Smurfs added
  
• all of these items are moved to the parent category
  
• the Smurfs category is deleted
  

Things to consider

• The Smurfs category might have sub categories
  

You might consider having a check box not to delete the category or warning saying it cannot delete the Smurfs folder because it is not empty on so on......

Also it might be useful having Tags to category

thanks