Ok, so the gist of the WBC is that enabling a sin is pretty much as bad as doing the sin yourself, and that in a Six Degrees of Separation way, enabling a sin-enabler be-sins you as well. They cite the Old Testament anti-homosexuality bit as sinful, and blame the US government as sin-enablers for not opposing homosexuality, and blame anyone who isn't against the US government as sin-enabler-enablers.
I didn't say it was a good gist, but it does sort of follow its own internal logic.
My question (that I probably couldn't e-mail the WBC to find out about) relates to how redemption and atonement really plays into the Bible quite a bit. OT, most of the stuff that was on God's Peeve List are things that will put you in the metaphysical doghouse for up to a week, but then you're fine. NT Gospels, you basically just have to apologize to Jesus/God and you're fine.
The WBC's actions seem to imply that they don't acknowledge these paths to redemption and/or atonement, though, since their take is that you're going to Hell and there's nothing you can do about it. I know a lot of left-field sects tend to cherry pick which parts of holy script they decide to ignore and which parts they decide to emphasize (sometimes for the better -- Anabaptists are generally pretty cool), but this redemption bit seems like a pretty major thing to opt to ignore.
UPDATE! It was a slow night at work, so I had some espresso gelato and did some research. They're Calvinists!
Ok, in broad-strokes, the gist is that sorry, Jesus probably didn't die for your sins. He didn't die for all of humanity's sins, nor for all Christians' sins, nor even for the "right sort" of Christians' sins. Jesus died to pre-redeem the original sin of a select few who will never sin (if you seem to be in the Elect and you sin? Guess everyone was wrong about you being one of the Elect). Everyone else, no matter how pure they are nor how many goodworks they do, is going to Hell. Even if you live a just and righteous life, somehow 100% free of sin, if you're not in the Elect, you're still going to Hell.
Heaven is invitation-only, and God already printed up the guest list when Jesus died. He's not adding anyone to the list, but He's happy to cross folks off the list. And the list isn't very long.