-I would like to show the roof or floor diaphragm with a solid hatch
change the visibility settings of floors and roofs in the view template or view graphics override

-I want the walls above the floor/roof diaphragm to show dashed.
Assuming you are looking to the ceiling in a structural plan view you first set plan discipline to Structural and show hidden lines by discipline
Then make sure you can see your floor (with a hatch in your case) so this floor blocks the view from the walls above.
You need something to block an object or geometry to make it appear dashed.
Next you check your view range and make sure your top and view depth are covering about 10 to 20 cm above the floor level, so your view depth is actually cutting the walls above.
-I would like the walls below the floor roof diaphragm to show solid with a hatch pattern.
you can do this with multiple solutions:
1) as with your floor make a cut pattern with your walls:


If you want to specify a certain wall type you can make a filter.
Same principle as above but you can specify your wall type or wall discipline:

