I have a few questions about cv crew.

1st. when can I use lvl 60 planes, when my captain is lvl 60 or when all my pilots are lvl 60 or when one pilot is lvl 60.

2nd. How do I lvl my pilots right now I have 1 evasion, 2 with fighter ability and 2 bombers ability, shoud I have mixed? 

Greetings Rowns.