stephankn
(Stephan Knauss (he/him))
4
If you read the discussion page you will notice that building=yes is very common, the other tags are disputed.
So for now it is fine to stick with the established scheme.
Routing is a completely different topic.
neither a building polygon nor a node is connected to the road network.
Usually the routing engine will direct you to the nearest node. There is a lot of room for optimizing the routing. For example if there is a paring space near your destination it could ask if you prefer to route to the parking space instead to the building.
Or in case a building entrance is is possible to route you accordingly in case the building is at a corner.
I suggest not to mix it with landuse.
In a country like Germany it is easy to distinguish different landuse areas. In a residential area it is often not allowed by law to run specific businesses. So you will for example not find a car repair in a resident area.
While in Thailand there are areas that are plain residential or plain industrial estate, there is no clear distinction in smaller villages. People who run a business often live in the same place.
And for routing the landuse is not used at all.
Stephan