Let's get a few things straight:
1. I was not defending Blow's infamous "Stick that in your magic underwear" tweet. My post quotes Jim Geraghty making the usual double-standard criticism about which religions are mockable, then asks — asks! — if you'd like to see the counter-argument, that religion should be vigorously mocked, and links to Crack Emcee. I'm just setting up discussion there, not drawing my own lines about what I think people should be saying about religion.
2. My "Everybody Draw Mohammad Day" post is demanding that people look at a double-standard problem, using the hypothetical "Everybody Burn the Flag Day." You need to think about what you're doing when you decide to leverage your protest on deep reverence that other people feel.
3. I've never stated a general rule about mockery and religion. I don't have one. Comedy is a great and dangerous force. Most people aren't too good at using it. It can communicate good fun or extreme contempt. You can be a complete asshole with comedy — which you have a right to be, but if you go too far in that direction, you'd better be good! You're probably not as funny as you think you are, but if you want to go to extremes, you're stupid if you don't know there's a risk. Now, the riskiest stuff is also the funniest stuff. Ask Lenny Bruce. No, you can't. He died. Remember when Michael Richards tried to do that Lenny Bruce thing? His career died.
4. Instead of a pathetic and necessarily futile hope for rules for humor, let's think deeply about what humor is. Here's a classic starting point:
In Freud's view, jokes... happened when the conscious allowed the expression of thoughts that society usually suppressed or forbade. The superego allowed the ego to generate humor. A benevolent superego allowed a light and comforting type of humor, while a harsh superego created a biting and sarcastic type of humor. A very harsh superego suppressed humor altogether.... Freud followed Herbert Spencer's ideas of energy being conserved, bottled up, and then released like so much steam venting to avoid an explosion.5. Underpants.