No problem.  Yes, node or area are both ok for amenity, shop etc.  The only information you didn't have is that "area" is just a way that is closed into a loop to form the boundary, and the only object types (that can have key=value tags) stored in OSM are really node, way and relation.  So landuse areas, buildings etc are just stored as ways, although note you can also use relations (containing an outer and inner way loop(s)) to make areas with holes.