Ah, looks like I set the flag for opening the gate wrong. The lever is meant to open the gate, but you should also be able to open it with the lever. There was an encounter set up for Cathy to also be able to open it, but we didn't set the flag in the build.
The torch increases your minor score and casts a light, the waterwheel increases your major score. They don't interact more with the dungeon in this build, but we have plans!