I've been thinking about balancing the different crew, and if it is needed. Berserker appears too powerful when at ace rank, grease monkeys might prolong the game too much, range of snipers is too high, and so on.
I think that if you spend points on one crew member to make them extra efficient you can't spend points elsewhere and therefore it sort of equals out.
But some options are: snipers have a limited amount of bullets, depending on rank, and bombers get to start with more bombs as they go up in rank.
Or, points can be spent on more bullets and bombs, so you can have a high ranking sniper but with less bullets, or low ranking sniper but with more bullets. I prefer this option myself. So a sniper might start with 3 bullets for his high powered rifle. Spend a point on ammo and get another three bullets.
Do the same with bombers (start with 3 bombs, spend a point and get another bomb, or another three?). Every crew member has a revolver with 6 bullets in it as well.
House rule it to pieces. It's kinda designed that way.