I think it's safe to say that all bikes, sold in USA, have an engine cutoff switch on the right side of handlebars. You will play with it in the MSF course. I don't think bikes have a cut off switch like what is found on jetskis.
Don't obsess over dumping the bike. I am also a new rider and find my TBA to be very well mannered and tolerant of me. I did dump her twice (early on), but they were both very low speed, no harm to the bike (except the stock exhaust) and it was strictly my fault. If anything, my pride was hurt more. But just made me want to get back on and improve myself.
Definitely heed Soren's advice and go sit on both bikes at a dealer. Look them both over carefully. Ask alot of questions, don't feel foolish. Everyone was new at this once.
I prefer the more upright seating of the TBA vs the SM. It was a very comfortable ride on my "little excursion" this past Saturday (racked up ~250 miles on a wide range of roads).

I am not looking for the "go fast" bike. I am a more conservative rider, especially as I am still learning.
Steve