Is there a way to edit terrain and buildings in the "Coaster Builder". I am looking to build a coaster with a covered staging area and queue. Any info on this would be greatly appreciated.
Nope. The editor only lets you build the rides. All the extras have to be added in a scenario.
You can make a dummy no money scenario to build the ride with the scenery that you want. Who cares if they close the park if you only want to build a ride to save it for dropping in another park.