In my system it seems, that gliss doesn't create a Trigger signal (at least in Mode 1 or 2). Am I missing somethning?

Where do you expect to receive a trigger?

In Control and Record mode, when the first selector is in Single Slider or Dual Touch, the bottom output (and also the top if dual touch) is the touch size. That output is proportional to the touch size (i e.: the contact surface of the finger on the touch strip), scaled by the touch sensitivity control in the global menu. If you set touch sensitivity to the maximum, then the output will behave like a gate.

If you are getting a signal that doesn't quite fill the output range you can increase the touch sensitivity control.

I wanted to connect 1 output to pitch control and one to amplitude control and trigger. When I use an external trigger, I can hear the notes, but using amplitude out as trigger, I can't hear anything. Measuring the amp. out gives signals lower 5V.
I'll try to increase the sensivity.

Also ensure that the output voltage range for the channel is set to 0V:10V.