I just had a few questions after watching the episodes again... Cant either the byakugan or the sharingan see the kyubi inside Naruto... and if so how come Neji didnt see it, or sasuke for that matter

Does rock lee just not have the ability to use Nin or Genjutsu, or does he have no chakra at all..?

Also, if Naruto failed the Acadamy exam 3 times, does that make him 3 times older than all the other rookie Genins?