Another card I "found" again after flipping through my box: EE. EE solves the problem of Deed being a bit slow, but EE is great against Tempo, especially Goose/Delver. It can be easily cast, doesn't need 2 colours (since we'll be EE'ing mostly on 1 or 2, but with birds we can do 4 for Jace in case) and is a tad faster. I may try 2 in the main, with 2 Deed in the board. Also helps against Maverick a bit (hitting their 2 drops can be nutty, or killing tokens/stuffs).
Yeah, Ghastly does have that terrible downside of being shrunk, but I think in the tempo matchups, where you're valuing speed/efficiency, I think Demise takes the cake. Obviously Path is better since the GY restriction isn't present, but putting a deck like Stoneblade ahead by a land is a fucking disaster. T3 Jace is not what I was planning on :P
I don't think Hymn is too slow, but if you were not getting there with Hymn in your meta, that's understandable. I mean, part of this deck is 8 pieces of discard to try and fudge your opponent around. I think if you're cutting Hymns, cut Vindicate for Pulse. Since you're now never on the land denial plan, Maelstrom Pulse has possible extra value here.
-Matt