With regards Pre-Departure Inspections
I have worked for 3 operators and on 2 different aircraft types.
When doing the Airbus type rating for an overseas carrier, the walkaround training involved a group of 12 of us doing a zip about the airframe with an F/O from that carrier, making sure that everything looked in place, looking at gear pins and so on. And that was it. No mention of cowlings, no videos of best practice etc...
On joining my current carrier, the assumption being as a DEP I was Airbus trained meant no check was done of my knowledge, nor a proper physical observation of it.
Only after years on the fleet and reading of my own, asking other Captains and so on, do I feel better qualified to know what to look for in a walkaround.
And I've always considered myself to be a diligent pro-active pilot. Worrying.