Question: I've noticed this in other Anime, but I see it a lot in Naruto; quite frequently the characters run with their arms straight behind their backs. Is there any reason for this? I spent a little time in Japan but I never saw anyone run this way.
Question: Why were the preliminary trials for the Chunin exam done as single elimination? It would not really cause the best of the best to be chosen because when two strong Ninjas fight (like Gaara and Rock Lee) one has to lose, while when two weak ninja (Sakura and Ino) fight, one gets to go through, only to be guaranteed failure. How is that fair?
Answer: Out-of-character, because single elimination is the most exciting format for the viewers of the anime. In-character, a possible reason is that the failure of single elimination to correctly identify the second and lower places was only recognised relatively recently - there is an essay by Lewis Carroll (yes, that Lewis Carroll), describing the problem in detail, written in 1883. Ninjas were around in about the 1300's, so it probably hasn't been discovered yet. Of course Naruto's history might not match real history but if you depart from reality then there can be no answer but the out-of-character one.
Question: How is Naruto able to easily create dozens of shadow clones when he needs to, but will sometimes struggle to create just a few.
Answer: Gaara contains a lot more chakra than Naruto expected, besides Gaara is extremely strong.
Answer: That is just a style used by some animators. It is easier to keep the arms in one position than to draw them in motion. And it makes it look funnier.
papajim