I love the poster, keeping in mind that it clearly seems like a teaser poster (and to that end, for simply listing the amazing cast, designing it such that it seems like they're all being piled into a house with it's roof blown-off, it does a great job aptly teasing me to see it, at least.)
Also, the color scheme brilliantly calls to mind the sweltering heat of the play. It's serial-parakeet-killer-hot out there in August...
As for it being a comedy, well yeah... I actually thought the original production was one of those rarities in theatre: a play that so roundly rejects genre. It was comedy, tragedy, drama, melodrama, farce, romance, elegy, state-of-the-nation, kitchen-sink... it's a titanic script that refuses to be bound to the confines of one genre.
Words don't deserve that kind of malarkey. They're innocent, neutral, precise, standing for this, describing that, meaning the other, so if you look after them you can build bridges across incomprehension and chaos. But when they get their corners knocked off, they're no good anymore…I don't think writers are sacred, but words are. They deserve respect. If you get the right ones in the right order, you can nudge the world a little.