I suspect that the confusion with 'The Devil's Courtship' arose because Child 2H and 2I were named by Motherwell as 'The Deil's Courtship' and 'The Deil's Courting' respectively. 2H is an innocuous 'Cambrick Shirt' variant, but 2I (from an Ayrshire collier) is more sinister: it belongs to the Elfin Knight / my plaid awa' strain, but instead of an elf knight, the protagonist is 'an auld, auld man' (probably the Devil) who responds to the lady's successful wit combat responses with the lines:

'My curse on those wha learned thee
This night I weend ye'd gane wi me'

'The Devil's Courtship' does indeed belong with 'Paper of Pins' / 'Keys of Canterbury'. I put together a version a few years back.