Show different line styles

[pics.munmun]

[barthbradley]

Is the View Range Cut Plane above the pony wall viewing the cap?  You could use Show Hidden Lines for this. 

About Hidden Lines | Revit | Autodesk Knowledge Network

Regarding the taller Walls; they should show up in Plan View using Cut Line settings.  That's typical solid.  Is yours not solid?  

[ToanDN]

Set the view Show Hidden Lines to All, or use Show Hidden Lines tool and manually pick what to be shown as hidden.