1) Haku & Itachi / Gaara & Kabuto / Pain, Orochimaru & the Kyuubi demon / In descending order. I like those within brackets equally. My top 4 shouldn't need explanation excluding Kabuto who's brilliance I admire. While characters like Pain and Orochimaru give off cool & dark vibes, their personality traits aren't the most interesting or admirable. (;
2) Dynamic Entry! XD
3) Neither at the moment; I haven't kept up with the manga.
4) I KNOW it will be Danzo because of all the spoilers. >_>/)
5) Sasuke completely lost his cool, Sakura and Ino are simply irritating, multiple characters are general perverts... There are too many characters with disgusting traits to decide on a single 'worst character'...