I'm going to have to go with James on this one. If it's knee-slapping, grab your ribs, roll across the floor funny and then you slap a serious ending on it, it's gonna be hard to make it work. You'll rish losing readers. There needs to be some undertone of seriousness throughout. And really, isn't that the point of satire? To poke fun and create awareness in a humorous way about the social/religious/political/etc. things around us?
As for the Tyler Perry reference ... can I respectfully disagree? His movies are poorly written and horribly uneven. Please don't use his format as a way to decide how to balance laugher and tears ...