Re-reading the title of your post,
These steps to configure your Guest as a tabletpc to enable “touch” gestures replacing click mouse events only addresses the mouse, it won’t do anything for sharing clipboard contents.
AFAIK libvirt should support a common clipboard between Host and Guest by default already, if it’s broken then you may want to mount a shared folder and paste content to a common storage.
I describe how to set this up with this article
https://en.opensuse.org/User:Tsu2/virtfs#Overview
TSU