A treacherous trench, named for its users; a vertical entry for some lesser gentry- best pay attention if the cover’s askew, for else it might mean the last of you

Depending on my size and my makeup, I might hold curtains or power nuclear reactors.

I’m public transportation for witches, and the reason dust never truly settles on the floor.

I get hot, release steam people wait patiently for me to finish. What am I?

I stop arguments before they start by politely saying, your yard ends here.