Itachi and Kisame were the only 2 who respected eachother in Akatsuki, i understand why you said this because Kisame is more of a i love to fight type of person and Itachi is the more relaxed person, but they respected eachother.
Nah, the age difference between kisame and sasuke is too much,
tbh, to me it would've looked like a child entered akatsuki...compared to the other grown up members