wacom/touch/pen and mouse cannot be used at the same time

First off, it was difficult to get the wacom pen working that is included in the lenovo x1 yoga. I had to manually edit ~/.config/inkscape/preferences.xml and set the relevant entries to "screen" therein. There is a bug in the GUI configuration that does not allow to set the wacom pen to "screen" without manually editing the xml* - the pen is useless without this.

Now pressure sensitivity works. However, I can use my pen but the mouse is severely handicapped - it's not possible to select with it in the work-area, but only with the pen. However buttons can be clicked.

Zooming with the touchpad by ctrl+two-fingers-up/down does not work. I do not understand why the mouse/touchpad needs to loose functionality in order for the pen to work. This is not so in gimp/krita or any other application. There the pen adds functionality but does not remove it.

Using the touchscreen with my finger instead of the pen also does show the same behavior as the mouse: clicking menus works, but not drawing/selecting in the work-area.

This behavior, together with the UI-Bug I mention at the beginning and the amount of bugs concerning wacom/pen/touch in the inkscape bugtracker somehow leaves one with the impression that inkscape has a problem with different input devices.

To sum up: the pen works flawlessly in krita, myPaint, after some hickups also in gimp and any other application that I use - except inkscape.

I am using inkscape 0.92.1 on linux (mint 18). If there is other information that you might need, then I will try to provide that.

Regards

--
* Just in case that my manually editing of a file might be the cause why this does not work:
The relevant, manually edited part of preferences xml is as follows.
  <group
     id="devices">
    <group
       id="P:Wacom Co.,Ltd. Pen and multitouch sensor Pen stylus"
       mode="screen"
       axes="x;y;pressure;xtilt;ytilt;wheel"
       keys="" /> **
    <group
       id="E:Wacom Co.,Ltd. Pen and multitouch sensor Pen eraser"
       mode="screen"
       axes="x;y;pressure;xtilt;ytilt;wheel"
       keys="" />
    <group
       id="P:Wacom Co.,Ltd. Pen and multitouch sensor Finger"
       mode="screen"
       axes="x;y;pressure;xtilt"
       keys="" />
  </group>

**the string in the keys-attribute gets filled with hundreds of seemingly useless and repetitive letters like lt;lt;lt;.... which I also deleted by hand. The rest I left as it was.