I would appreciate any advice I can get, or any thoughts about how this deck may work. At the moment I can only play solo, and I usually play on standard.
If you are going to use Dark Horse then you should probably also include Fire Axe. Also, Events that cost 2 (or even 1) are unplayable if you intend to keep Dark Horse online. If you are already planning on doing the Desperate skill thing, I would probably just drop Dark Horse and include something like Trial by Fire or Fight or Flight as an alternate stat booster.
I personally prefer Take Heart over Emergency Cache as Calvin should have no problem failing tests in the early game, and the extra card draw will help a lot with finding those Meat Cleavers
The only damage soak you have in this deck is a single Trench Coat (and Until the End of Time). I would probably want to include at least something else that can soak or heal damage for the 0XP version.
My suggestions: