Hi d_berger, 
Thanks for the comment.
In cases like these, I try to map what's on the ground, as it says in the OpenStreetMap wiki: https://wiki.openstreetmap.org/wiki/Good_practice#Map_what's_on_the_ground
(i.e. ground situation is more important than official source)

I live close to Oerlikon, and I regularly pass through this area. In this case, it was clear to me that this part of Edisonstrasse has sidewalks and curbs (and some parking that separates them), whereas Welchogasse clearly does not (it only has a single space that is shared by pedestrians and vehicles). So even though they are both classified as living streets, where pedestrians are permitted to use the "Verkehrsfläche", I though it would be appropriate to map the sidewalks on Edisonstrasse, along with the appropriate crossings. This also better reflects the reality of how people walk along this street.
Let me know what you think!

BTW thanks for pointing out on some of my other edits that the "foot=use_sidepath" is better than "foot=no" on streets where sidewalks are explicitly mapped. I switched to using this tag now.

Cheers
Chris