... cross the street anywhere, you just might get a ticket if the Gestapo is watching. The car still has a duty not to run you down.

179(1)). Section 180 provides that pedestrians do not have the right of way when not in a crosswalk: When a pedestrian is crossing a highway at a point not in a crosswalk, the pedestrian must yield the right of way to a vehicle. (Motor Vehicle Act, RSBC, 1996, c. 318, s.
In other words it's noted -
"if you are walking parallel to the road and along a sidewalk and come to an intersection, so long as you continue walking straight you will be in a crosswalk as you cross the road." ( ICBC claim information site. )

So basically what OP said ... if you are at a corner / intersection it is considered a crosswalk.

Not quite - only when the pedestrian is travelling in the same direction as the traffic, while encountering all the cross streets.

...one reaches the intersection and turns 90 degrees to their previous path of travel, they are again 'travelling parallel to the roadway'. The stipulation is to render illegal diagonal intersection crossings, unless specifically allowed by road markings.