Taking a new hotend into operation (cleaning, forming, etc) When installing and using a new hotend for the first time, which steps of action should be taken before. This will probably be more applicable to chinese clones than to authentic products (is the statement true?): Should a certain cleaning procedure be carried out (removing swarf/shavings for example)? Should mechanical precision be controlled and if necessary improved (de-edging and nozzle size are two things I could think of)?

I know the topic How should I clean my extruder when changing materials?, which is a nice addon read, but I am concerned about brand-new extruders.
I haven't done anything special to set up mine. But it's probably worth doing a general cleaning. I'd swab it off with alcohol, including running a q-tip or similar inside the fiber feed path. Then blow out the nozzle with compressed air to make sure it's clear.

You could measure the nozzle diameter by fitting fine drill bits in to see which is the largest one the passes through freely. Be sure to measure how much fiber your extruder really takes in when you ask it to extrude a certain length -- but that's about the extruder, not the hotend per se.

Finally, I'd check the insulation, if any. I got a couple hot ends that had big gaps in/around the insulation. I've found that "high-temperature gasket maker" is great for improving insulation (depends, of course, on the shape and design of the specific hot end.