"Focusing on this particular argument, gay marriage is not useful in any way, shape, or form, be it economically, socially, or politically."
Lets see, they vote and participate in campaigning (political), they work, purchase homes, cars and set up households (economic), they make friends, host parties, go to clubs, concerts, etc. and give their rime and money to charity functions (social) Strike one.
"Not only that, for those who are blind, deaf, and dumb, once you allow gay marriage in, what is there to stop the floodgates from opening? I'll speak to the most obvious movement that is riding the coattails of gay marriage, pederasty and their 'club' of NAMBLA, the North American Man Boy Love Association."
WTF is wrong with your mind that this is obvious to you? Stay the hell away from my nephews, you sicko. The same nephews that we trust our GAY brother with implicitly, and that he would go to the ends of the earth to protect. Every gay person I know thinks pederasty is disgusting. Strike two.
"Once you've legalized gay marriage, how can you deny them the same rights? How can you deny pederasts, pedophiles (which are distinct from ephebophiles), child pornographers, bestiality enthusiasts, and all the other assorted ills of society when you've already granted legitimacy to another unacceptable thing?"
Because children and animals can't give consent? Because loving a consenting adult of the same sex has nothing to do with any of the above? Because most gays I know would gladly string up anyone who would harm children or animals up by the balls? Strike three, you're out.