Do pilots of airliners and jumbos do a walk around preflight check for every flight?
NO, not all airline pilots do a walk-around for every flight. 

At my airline, maintenance personnel do a "Pre-Departure Check" (PDC) before each flight from all main bases on all wide body aircraft. (A330, B767, B777, and B787)

The PDC includes: 

1) a walk around 

2) a check of critical systems

3) a signature in the Journey logbook

As a result pilots very rarely do a walk around on the wide body aircraft. 

If we happen to land somewhere without company maintenance, then a walk around would be done by the pilots. If it were an ETOPS flight, we would also have to make an entry in the Journey Log Book stating that the APU oil level was checked by noting the EICAS APU Oil Quantity reading. 

In addition to the maintainance walk around, the ramp crew also does a quick walk around inspection just prior to push back.