I would suggest having 2 BO's since germany have 2 battleship lines, this will also allow you to level your supports up relatively evenly. While also allowing you to have a good number of suitable AA/gunship platforms that will help you understand how german ships are played. That and the O-Pro2 has one more support slot over the bismarck and better AA spacing. Plus with having 2 BO's your supports will generally be a bit farther ahead of one BO or both BO's so when you reach BB6 your supports, and scout should be 115 and ready to go.
you can get by with all base 11 or base 10 crew for germany if need be, i had less that spectacular crew, i only have 1 elite i got off a fleet mate ages ago and use a resty on my kaiser. Doesn't hurt my performance in the least however keeping your crew up to snuff is a good thing to do. Also for AA the german gunners cap early so class them on time, and if you can ALWAYS run AA on your battleships, not only will it give you some ability to kill incoming bombers and scouts but at times of no support it can kill off some fighters so you can launch a scout.
I will also add that try to have your gunners near level 100 by the time you reach the H39, otherwise you will not enjoy the ship all that much due to it's poor low level spread. even with elites it has issues with that.
