welcome to OSM!
please review:
I've changed highway="maxspeed=20" to
highway=residential
maxspeed=20
osm.org/changeset/35302028

Okay, so I'll change the typo mph to kmh
tomorrow.

okay, ich habe es nur bemerkt, weil ich versuche, seltene highway tags zu konsolidieren. Mir wäre es daher lieber,
wenn Du es änderst.

okay, I just wondered because way=firewall is only use here .

please review:
maxspeed=5 kph is not clear,
do you mean 5 mph or 5 kmh?
Appears on 8 ways in this changeset.

please review:
I've changed "20 kph" to "20 kmh" and
40ton to "40 t"
osm.org/changeset/35290719

please review:
maxspeed="40 kph"
Is that 40 mph or kmh ?

thanks for the quick feedback.

I would use
highway=pedestrian or highway=footway with area=yes for this.
Which routing software supports way=yes?
It is rarely used.

please review:
what is meant with way=firewall ?
Maybe
man_made=cutline ?
osm.wiki/Tag:man_made%3Dcutline
In Bing the way looks more like a normal
highway=track now.

please explain;
what does
way=60708167
mean?
osm.org/way/294027837

please review:
It seems you wanted to create a
type=multipolygon relation, but something went wrong.
See my changes to fix this:
osm.org/changeset/35288112

please explain:
what is meant with
way=yes ?
osm.org/way/278365183

please explain:
what does way=yes mean ?
osm.org/way/267875373

please review:
What does
way=yes mean ?
osm.org/way/263170655

please review:
I've changed way=residential
to
highway=service
service=driveway

please review:
what is meant with
way=pedestrian tunnel ?
If there is a way through the building
you may add that with
highway=footway
tunnel=building_passage

osm.org/way/62343104

please review:
This seems to be an indoor elevator ?
osm.org/node/3185979548
The node should be tagged with
highway=elevator, the way(s) from and to it
with highway=footway / corridor

please review:
you have added some tags with
higway=residential instead of highway=residential in this area.
I've changed them to highway=residential.
OK?

please review
osm.org/way/20132873
This doesn't look like a
highway=escape to me.
Seems to be a road that help to do a u--turn?
osm.wiki/Tag:highway%3Descape