Questions about recent episodes

[tensai]

yup, chakra can be seen by anyone if it is focused in a large amount, for example, Haku notices how Narutos chakra changed from blue to red

I dont think that the actual demon from of the Kyubi can be seen with neither the byakugan or the sharingan.
Rock Lee is just weird, but cool. Certain people are good and bad at some things, it just happens that he is super bad at ninjutsu and genjutsu.
I also believe that Naruto entered the ninja academy before anyone else. I dont know if I remember correctly, but during the Naruto vs Kiba fight, there was a flashback showing some people talking about Naruto...i cant really remember what they said but it might be there and have something about how Naruto was held back a lot

[LostAngel]

Neji saw the red chakra but didn't know it was from the Fox. I think some high leveled ninjas can sense chakra and people intents from others. Like Kakashi knowing that Gaara was on the other side of the rock. Sasuke didn't know but he did. I've only notice advance ninjas ever saying anything. Plus most can tell different chakras from another right? And if someone knew that he had Kyuubi in him and he was calling upon a completely different chakra its obvious.

As for everyone being amazed... just because like Neji-Aniki-sama said it amazed them that he was able to produce chakra after what Neji did.