An oratory is simply a small room intended for prayer.
The idea that vampires have no reflections, and that they fear crosses, are both traditional ideas held for centuries. In Bram Stoker's Dracula, a famous passage recounts Jonathan Harker's realisation that Count Dracula is not reflected in his mirror:
"Suddenly I felt a hand upon my shoulder [...] and I started, for it amazed me that I had not seen him , since the reflection of the glass covered the whole room behind me." p26.
Stoker's vampires also cower back from crosses and garlic. Rice does not allow any of these traditional ideas to affect her vampires.
Stephenie Meyer takes the heresy even further: Twilight vampires are quite happy in sunlight.
Sugar increased in popularity enormously in the 18th century. Grown and refined across the New World, it was a source of great wealth for plantation owners.
Sugarcane cultivation drove a surge in the use of slaves, and in 1791 abolitionists in Britain organized boycotts of slave-sourced sugar. This may have been the first time consumers used their purchasing power to confront an ethical issue.
Towards the end of the 18th Century, duelling fell out of favour in the USA and gradually declined.