Unable to answer "Does this street have a sidewalk?" for osm.org/way/20179160 via StreetComplete 33.1:

There is a footpath along both sides of Halls Close, but it is not a "pavement", When the estate was built (1990?) the less used footpaths in Halls Close, Barn Close, Scholar Place and other local streets were left as grass. AFAIK, this was just a cost cutting measure.
This is complicated by the fact that the highway boundary markers have since eroded and several house owners have planted shrubs in the grass footpaths and made them impassable.
Street Complete needs a "grass footpath" option or a way to change the footpath surface.

The crossings and bike lanes have all changed with the recent development

via StreetComplete 33.2

The Abbey Guest House was historically the guest house for Dorchester Abbey in medieval times.
It should not have a "guest house" symbol implying that it is currently a business offering accommodation. It should instead be marked as a historic building which now houses the tea-room and museum.
These are both marked, though the tea-room is at the eastern end of the building where the marker is.

Unable to answer "What is the house number of this building?" for osm.org/way/254761803 via StreetComplete 33.2:

can't see a number or numbers from road

102 was a single detached, unlike all the others in Arthray Rd. It has been extended to create another house.

via StreetComplete 33.2

Unable to answer "What is the surface firmness of this track?" for osm.org/way/794796500 via StreetComplete 33.2:

private driveway