When I think of the scene where the Aliens are biting the Queen to break her chains, I think of the scene in Alien Resurrection where there are three Aliens being held in an observation tank. Two of the Aliens attack and ultimately kill the youngest/weakest/whatever Alien in the chamber in order to use it's blood to break out of the chamber. The Aliens are very much like ants in this regard... they aren't afraid to harm, maim, or even kill a member of the hive if it means the survival of the hive (though in the instance of the Aliens biting the Alien Queen, the goal isn;t to maim or kill her... it's to free her from her bonds). I also recall seeing/hearing something somewhere that the Predators were giving the Queen some kind of chemical that inhibited her ability to lay eggs except in 100-year intervals. With that in mind, I'm willing to accept on faith the Predators have the knowledge and technology to have acid-proof weaponry and equipment. Taking an Alien Queen, chaining her up, and giving her an egg-producing inhibitor/drug does imply a high degree of Alien knowledge. But even with acid-resistant weaponry and gear, the whole "rite-of-passage" scenario is still plausible. The teenage Predators are still in a high degree of danger while inside the Pyramid. They are just better equipped to deal with the upcoming challenges. Maybe one of the purposes of the "rite-of-passage" is to teach young preds that in the hunt, you have to rely on more than just weaponry. Maybe that is the final lesson a young Predator has to learn before becoming "a man". This is all just hypothisis though... we'll know all the details in 5 days. ;-)
