I padded the main floor, and didn't pad the riser or stage....
I used an office/home office carpet (trafficmaster) that was designed for glue down, so it wasn't problem (i didn't install it, had someone do it).
I didn't pad the riser/stage for 2 reasons:
1) for the stage, my a/v rack is on casters, and slides out of the proscenium...the rack is heavy, and rolling it on carpet with pad would be difficult...also, no pad means less compression when the rack is stationary (99.9999% of the time).
2) for the riser, I was concerned about how the transition would go from padded (top surface) to unpadded (where the carpet wraps on the lip)...