Shylock wishes Bassanio to be ruined because he wants to take revenge upon Antonio and can do so if Basanio and Antonio fail to repay the loan on a stipulated date.
Hope this helps!
Deluge means a severe flood, so the opposite would be drought, A.
I think the author chose to start the book 19 years before the main events of the story so the reader could absorb things. The author technically wanted the reader(s) to understand something before reading the real story.
