I haven't read the whole thread but some posts.

As hugolp pointed out, the increase in margin requirements is probably what had caused more damage. Remember the las silver sudden drop (April/may)? They did the same back then, precisely in the middle of a bull run.

Gold hasn't any economic value? Of course it has, it has had monetary value for thousands of years. The worse other moneys do, the better for gold.
It would also be extensively used in industry if it were as cheap as silver.

USD deflation won't hurt gold, because it is cash, not credit. At the bottom of the deflation you sell the gold and buy investments with yields on the cheap.
But will we have deflation? I don't think so. Hyper-inflation and the destruction of the dollar (at least as the world reserve currency) is the most probable outcome in my opinion.

If NATO had not invaded Libya, gold would be even better and USD even worse. But if you suggest you're going to sell your oil for anything different than USD you get a bullet in your head. Gadaffi did it (he even proposed the golden dinar as a supra-national African currency) for gold. Saddam did it for EUR. That's what makes USD the world reserve and not the US economy, which is no longer the soundest in the world.

Anyway, QEn will stop it all. With each iteration they need to print much more to prevent deflation. And exponential functions don't last forever.
I don't plan to sell my silver until the USD has collapsed. And I'm completely certain that will happen sooner or later. The monetary value that the USD contains will move to other places, and precious metals will get a great part of that value.
On the other hand, if they allow deflation to happen, gold won't suffer a great loss, probably rises too.