There's a very thin line between "poking fun" and "mocking". The first is making a few jokes about theism and such without any intention other than "to have fun". The second is actively yelling in their faces "LOLOLOLOL YOU GUYS ARE SO STUPID!" which, IMO, says more about the person who's mocking them than the theists.
Aha. OK, you seem to be using an extremely precise and specific definition for "mockery," something like "An extremely boorish and witless form of ridicule, often delivered in YouTube comment-speak." Using that
definition, I agree with you, we shouldn't use "mockery." I'm going to guess that you also have extremely precise definitions for things like "snark" "to poke fun at" "to make fun of" "spoof" and so on, and consider each one to be a completely distinct ethical issue concerning its use WRT Christianity. Rather than trying to pierce the semantic thicket, I'm going to provide examples of the kind of thing(s) I'm in favor of, and let you slot them into your classification system as you see fit. Once you have done so, please mentally perform a "Search/Replace" on my previous posts, replacing "mockery" with whatever term(s) you accept as fitting what I'm talking about.
Jon Stewart (riffing on Glenn Beck):
Lewis Black (also riffing on Glenn Beck):http://www.youtube.com/watch?feature=endscreen&NR=1&v=i1hTZopwvuA
Lewis Black on evolution vs. Creationism (note the audience reaction):
Christopher Hitchens on Jerry Falwell's death:
If you think the above are acceptable, then we're agreed, and we can move on to some of the other issues I raised in the OP.