Thank's for the quick reply and in-depth explanation. A clearer description in the Wiki would be great. From now on I will add the address to the building as well as the POI.

Dear Kevin,
thank's for your advice. I really try to get my head around how to tag addresses in a proper way for a long time and it seems to me like everybody is doing it in a slightly different way. However, the OSM wiki suggests otherwise:

"Usually address informations doesn't need to be duplicated, i.e. there should be only one addr:housenumber=* per street and house number" (Source: osm.wiki/Addresses#How_to_map_addresses)

and this forum post explains why:
"We are dealing with a geographical database under the covers and all the data consumers should easily determine that a point (POI) within a polygon (building) shares the address of the polygon. So it is not necessary and many consider it potentially harmful as if something changes it is one more thing that needs to be maintained. The general philosophy is to enter something only once. And there are some QA tools that will definitely flag that as an error to be corrected, so don't be surprised if some remote mapper fixes that for you." (Source: https://help.openstreetmap.org/questions/48735/address-information-in-poi-and-building)

Do you still think the address should be duplicated and be added to the building as well as the POI?

Hi,
I changed Kamptaler Rundwanderweg from bicycle=designated to bicycle=yes, because "designated" would imply a proper cycleway (as described here: osm.wiki/Path_examples), which I would say this path is not. If it is part of a mtb route, you maybe want to add the tag "route=mtb".

Hi,
thanks, you are right. I wanted to add "Drinking Water" with the MAPS.ME app, but this tag was not available within the app.