What am I missing if I don't have a Sphere account and/or active internet connection on my CTOUCH touchscreen? What if I do not have or want internet on my touchscreen, because it is not allowed to use the internet (e.g. for government institution)?

You can create a Sphere account on any (mobile) device with an internet connection (with the exception of smartphones with a low-res screen). So, no internet on the CTOUCH screen does not have to be the reason not to register for Sphere.

The connect code that you need during the installation of a CTOUCH touchscreen in Sphere, could also be used on a touchscreen that does not have an active internet connection (yet). But an active internet connection is used to automatically register your CTOUCH touchscreen. By not registering your CTOUCH touchscreen, you miss the possibility to extend the standard warranty and remote management and managing. Also a Heartbeat subscription is not possible *NOTE (security) updates can not be installed without an internet connection!