I don't think it will look lame. You could have both plaster & stone in a real house, just not as likely in North America
I use Scene Setters as well. I think they give a lot of bang for the buck. They work great transforming my unfinished basement. I used the wallpaper & wainscoating on most of my largest area, but didn't have enough to go all the way around. I had the stone & skull pillar set around so I used that along one wall. To ease the transition in the two corners I brought the stone around & then had the wall paper kinda hanging down over it & made the edge jagged. I was going for the effect that all the walls are stone, but were covered up in a remodel at some point.
I was worried about mixing the scenes as well, but people said it looked great. Works for me!
Are you having a party?