Constable
hi, routing wise this thing looks legit to me, to be honest it looks to me like this changeset improved things http://nrenner.github.io/achavi/?changeset=54453945 as it looks like the mapper removed a straight footway which was crossing playgrounds and stuff like that. Self intersecting/overlapping footway sections should definitely be fixed, you're right.
This parking lane ( https://www.openstreetmap.org/node/4911554694 ) should be connected to the footway added with that changeset you pointed out, otherwise routing wont work. I didn't really have a look at the other(s) changeset so far.
Thanks for those notes!