Pressurization controls on all Kingairs (except perhaps for some early A90's) are extremely easy to operate. The same can be said for Cheyennes again except for some early II's. In the early models of those you have to select cabin altitude and then after takeoff select ascend, neutral at top of climb and then when ready for descent, reset cabin altitude and select descend. Not likely you'll run into that unless you get into something manufactured mid70's vintage.
There is not really anything to gain in using reduced thrust takeoffs in this catagory of aircraft and might get you into a bad situation one day if Mr Murphy raises his head and you have an engine loss as the gear is going in the wells.
If you reduce prop RPM first after takeoff without reducing torque first you will almost certainly exceed torque limlts. Torque will increase as you reduce prop RPM.