I just ordered a nest wifi and point from a Danish webstore. Receiving it, I see all info on the box is in German and French. Before opening it, I just want to make sure it can be used in Denmark and there isn't any compatability issues cross European countries? (Plugs are the same across the three countries and shouldn't be an issue.)
No, you should be good here if they're all designed for the EU.
Google Wifi and Nest Wifi units manufactured for use in the USA use the 5 GHz channel in a way that is not allowed in the EU and UK for example, but you're not going to experience that issue if all the units are for the EU.