1 - Kabuto wins. TheEvilOne already explained quite well why.
2 - Kabuto... Even if its 4v1 they don't represent a threat, he gets rid of them, one after the other.
3 - Kabuto. Kuchiyose: Kirikiri Mai is avoided using Earth Release: Hiding Like a Mole Technique, but this depends on the location too.
4 - Kabuto. 2 puppets aren't nearly enough to deal with him, he's very good at dodging...
5 - Kabuto. His taijutsu at that point was somewhat at the same level of Kabuto's (databook stats), except he uses Gentle Fist which could give him superiority, but, Kabuto has pills to increase his performance and Neji can't spam Kaiten to keep him at bay.
6 - Kabuto. I doubt Lee at that point could make more damage than a Rasengan, Kabuto's level of regeneration would allow him to survive, plus, after gates he would be too tired to continue the fight.
7 - Gaara. He has no way to touch him, while Gaara can easily crush him with the amounts of sand he can produce.
8 - Maybe Sasuke. 3-tomoe prediction would give him the advantage, plus, all the other damaging jutsu he has.
9 - Naruto...
10 - Can go either way according to Jiraiya and Oro. But i would give it to Kakashi around 6/10.
