Do not use 5mm pitch screws, except maybe the Z axis. To get 9m/min, you'd need 1800rpm, which you won't get out of steppers.
And you should be able to spin a 2510 screw much faster than 800rpm without whipping.
Accuracy won't be an issue.
Motor requirements depend on how much weight you are moving, what top speed you want, and how fast do you want to accelerate to that speed.
If you are going to spend over $300 per motor/drive for closed loop steppers, you could get at least 3-4x better performance from 400w AC servos for about $100 more per motor.