Frame size looks right. A 56cm bike would also fit you now, I would think, but you're going to get a bit taller. However, you might want to fit a shorter stem if you get a 58cm off the bat.

Crank length: don't worry about it. 2.5mm doesn't make any real difference (except to things like tyre and ground clearance, and even then, not much). I didn't even realise my bike had 167.5mm cranks until I was cleaning it and I saw the numbers stamped on the back of the crank. 

Saddle height: it'll probably be somewhere around that, but it depends how long your legs are, the thickness of your bike shoe soles, what length cranks you're using and how high the saddle rises above its rails. Again, don't worry about it. You can get it basically right by setting the saddle at a height where, with your heel on the pedal, your leg is straight without having to really stretch and/or tilt your pelvis. Then when you put the ball of your foot is on the pedal, your legs will have a slight bend at the bottom of the down stroke. That's your starting point. You can then make minor adjustments from there. (I know there are lots of theories on bike sizing, but I don't believe any of them. There's no scientific basis for them. They're just extrapolations of what seemed to work well for professional racers.)

So what are you selling