In addition to submitting my ideas for the next DLC's subclasses in the form, I've also gone ahead and written them up in a 5e format for anyone that wants to look them over or use them in a tabletop game. Or mod them in I suppose.
If added in game I purpose the Bard feature works like the favored enemy feature of the ranger, dealing extra damage based on your bestiary entries for the creature type. Plus additional damage equal to their int.
The 11th level Mountain Monk should have a bonus action "use power" to choose between the bonus damage types. Or a free action version.
Just about everything else should work about as is, I believe. Let me know what you think!