1 I would say Langy plays harder for low markers than for high markers. The pros and low markers struggle to break 75 yet high markers have 40 points regularly.
2 as for bunkers, where does it say bunker has to be soft and fluffy. sand type and grain varies with every course.
I would suggest not getting out its more to do with technique of not knowing how to adjust the bounce angle on sand wedge to type of sand.
3. Bunkers do affect slope rating The slope rating is based on number of hazards (penalty areas) including bunkers that come into play, thats why courses like frog or Yering has a higher slope rating than Royal Melbourne and why a course like Beacon hills with no bunkers has a low slow rating.
I already know my bunker play needs more work but I don't get much practice. Yes I know about using or manipulating the bounce.
I just mentally went through each hole on the Hills front nine at Beacy and every one except the 9th has bunkers. I'm less familiar with the back nine as we usually play the Lakes. At Warra there's only 8 bunkers in the entire 18.