yeah kakashi's katon: gokkakyuu no jutsu was unneeded, but it did allow him to show off a bit.... He's so broken sometimes it's not even funny.
......Too much information on the sharingan. Itachi already explained that in order to make full use of the sharingan you need a kekkei genkai as well as the sharingan. So you can assume that it was specifically made for the Uchiha clan who have the memory and the chakra capacity to deal with it.
Rasengan is NOT a wind type jutsu. They explained it in the manga already how it was just spatial compostion, not elemental. Naruto has only used it for something other than attacking in fillers.
I agree that the Ice type jutsu in the first movie was being used because of the environment. Otherwise They said it was Haku's water/wind kekkei genkai.
......there I'm done.