I'm only able to read this via iPhone currently, which is less than ideal for comic scan enjoyment, but once I'm at a proper computer, I'll give this the reading it deserves. I remember being very disappointed when it came out, purely because the teenage boy I was very much favored the ultra-violent-but-still-funny Mask by Arcudi and Mahnke (particularly LOBO/MASK), so at the time, I viewed this story to be a huge wasted opportunity of expectations and potential. The lack of magnificent slaughter made me sad. But I'm super-interested in giving this a read now, and I shall soon!
In the meantime, I've given our spirited discussion some thought, and it occurred to me that a lot of what you liked about Morrison's Joker... I've been thinking, that's what I'd like to see the SCARECROW be! The Joker as an unbridled nightmare made flesh bores me, but shit, that'd be a grand direction to take Jonny Crane! At least with the gas. Because when was the last time the Scarecrow was actually scary?