Dan,
This was a great idea, and just what I needed to fix almost everything. I opened up my raster file that I was using as a custom surface and found out there was no spatial reference. The projected raster had been moved to a temp folder, so that's embarrassing...
Using the GOOD raster this time I did bring it into an empty workspace and I now have a ground surface in feet!
The only situation I have left to figure out, and this is still part of my original problem, is why its still showing my Z-values in meters. This is strange to me because when I open these layers up in any other blank map, the vertices are shown in feet for the Z. For example; in the same Pro project I created a basemap tab and added one of these layers and the z-values read feet. But in my local scene, it's meters. I'm baffled, but about ready to just let it be since it's not actually changing the data values in the database. Let me know if you have any other thoughts, and thanks again!