This is active forestry plantation, with no evidence that its formally used for mountain biking, so I suspect all the clever names for the tracks are spurious. I have marked them all private based on signage from the Montreal Estate posted round the area.

Adult driving range with kids pitch and putt also on site.

The path carried on from here all the way to Upper Elmer's End Road.

via StreetComplete 30.1

Unable to answer "Does the bus stop Langley Court / South Gate have a shelter?" for https://osm.org/node/469773650 via StreetComplete 29.1:

I cannot see a bus stop here.

Can somebody from locals clarify the gate's access?

Meant 2 Bean cafe

Couldn't seem to find footpath from road - is that a footpath issue rather than a mapping issue?

Is there still a post office here?