Great intro and demos @Clemens Jütte, What is the best resource to understand overall architecture of Humanitec services, which regions are used, what data is stored where, I am UK based some organisations require UK hosting

Humanitec generally doesn’t host any applications, they still run inside your infrastructure. In terms of access needed there are different approaches described in more detail here https://developer.humanitec.com/integration-and-extensions/humanitec-operator/architecture/#modes-of-operation-humanitec-operator, which go all the way from direct access to no cluster access at all.