Welcome to OpenStreetMap and thanks for updating the map.

Although the iD editor you're using unhelpfully presents all the common access tags as if they all need to be completed, you usually don't need to change them on highway=footway lines. The default access allows pedestrians and forbids everything else. The other access tags are only needed where there are exceptions.

https://wiki.openstreetmap.org/wiki/OSM_tags_for_routing/Access_restrictions#United_Kingdom