The first question is linked to the second, in the sense that the power of the laser will define the possible cutting depth and working speed.
According to the manufacturer, you can cut up to 10 mm with a 22W laser, but this really depends on the material.
Personally, I wouldn't recommend cutting 10mm with the 22W laser as this would result in a poor quality cut and additional smoke/fire risks, but having tried cutting 6mm MDF, the cut was particularly clean.