Have not been here for months. Realized that Kiri got some nice functions. 
Thank you @stewart for all your effort.
#1 What can I do to minimize the paths between the cutouts of my part? The spindle does not finish cutout by cutout even tough I checked “Depth First”.
#2 When I export the gcode the spindle speed is set to 0. Any hint what I’ve missed here?
workspace_HeatSink.kmz (523.2 KB)
that is curious. I will investigate.
as for the spindle, your spindle macro is empty in your device definition. usually it contains something like
M3 S{spindle}
Thank you for your reply. I updated the spindle macro and it solved almost all problems. 
Drilling butRough (see attachment)workspace_Blende_0-5mm.kmz (2.1 MB)
The path for #1 is much better, when I do it with Trace.
By the way: Cool new features with the Drill operation. 
what’s wrong with roughing? I’m seeing the spindle command set properly.
Sorry, I was confused because of the first M3command, which is set to “0“ with Rough.
Rough Operation:
G54
M05
T1
G43 H1
M3 S0
G0 X0 Y0
G0 Z1.9900 F6000
G0 X0.0 Y0.0
G0 X0.4543 Y0.4543 F400
M3 S16000
G1 X1.1999 Y-0.1178 Z1.8243
Drill Operation:
G54
M05
T13
G43 H13
M3 S15000
G0 X0 Y0
M3 S15000
G0 Z1.9900 F6000
yep, it starts the spindle before the first cutting operations.