Normal wall switch + philips hue + fibaro? (Denmark)

They are very different. For one thing, the one you linked to is zigbee and the Fibaro is Z wave.

Most importantly for your use case, fibaro has some models which can accept two switches, not just one. In those models, the second input can be set up so that it does not control the current. All it does is send messages to the hub. So that’s the one you want, because you can use it to send a message to the Smartthings hub without cutting the current to the hue bulbs. Fibaro calls this “scene control.” (This is a Z wave feature.)

So everything in the manual which has to do with the technical specifications of the bulb will not apply. You are just using it to send a scene number to the hub.

Note that you still need a hue bridge. But that’s a completely separate issue. See the FAQ on that:

FAQ: Do I need the Hue Bridge/Hub to Use a Hue Bulb with SmartThings?