1) 2)
It's most common that the first two kanji is a surname, as in all your four examples, but one ~ four kanji surnames are also possible. (There even are five kanji surnames, but it's only two 左衛門三郎 and 勘解由小路, so you don't need to consider about 5.) You need to be familiar with Japanese names to identify it.
e.g.
坂東三津五郎 (surname 坂東, given name 三津五郎)
佐々木蔵之介 (surname 佐々木, given name 蔵之介)
長曾我部元親 (surname 長曾我部, given name 元親)
3)
Those kanji refer to 上等, 二等, 一等, 飛行 and 軍曹, respectively.
4) 5)
large 神風特別攻撃隊 > 第二御楯隊 > 第一攻撃隊 > 爆撃隊(bomber)・直衛戦闘機隊(fighter) small