Are there rules orconventions about the distances between buildings and ways, garden and ways, cycletracks and ways?
For example, if the garden is draw too close to the road, it goes “under”, and cycletracks become invisible…
Note that for a road, the way represents the centre line of the road. So if the garden or cycleway is for example 5m away from the road centre line, then draw it there.
Yes, this might mean the cycleway is obscured by the road on some map renderings, but that is a problem with renderer, which should be fixed / improved. Or use another map rendering which shows it better (eg OpenCycleMap).