Hi Christian, 1. We recommend the following layer heights: 0.1mm for HQ, 0.2 for standard and 0.25 for fast. You can go down to thinner layer heights (we printed up to 0,05mm successfully), but the quality does not increases enough to justify the extra time required. 2. The Z leadscrew is TR8*2, the stepper is 1,8°/rev and the microstepping is 1/16th. That means you can print at any layer height as long as it is multiple of 0,01mm. Hope this info is useful!