Glad he's got "only" gastroenteritis and hope he recovers soon.
As to addresses, I guess it's just tradition. You can imagine in the past it was "Take this to John." "Where is he?" "At number 12." Then later "Which street?" and only after that "Which town/village?" But clearly there's a lot of cultural variation. The Polish way is street, number, post code, town; or else village, number, post code, post town. The Russian way IIRC is town, street, number, post code. Other formats are surely used in other places.