the word filter has been fixed up a little black, it's a little more leniant now, lol, although I think it still filters out some words.
As far as chopper goes, I doubt he was blooded, he had no mark on his head. As far as the human skulls mounted on the spears that he had, well, according to Anderson in the DVD commentary, once a predator has killed enough humans, he then earns the right to participate in the blooding ritual & proceed to "the next level", that's according to him anyway.
As far as the second predator goes, well it seems to me that if he had all those skulls in his trophy case, including the alien skull, then he was obviously a highly experienced hunter. The blooding ritual might have just been performed by that particular clan in AVP, & back when the first 2 pred movies were made, the idea of blooding hadn't been introduced, as even the elder in predator 2 didn't have the mark.