I am an international graduate student living in Toronto. In two weeks, I am travelling to Peru to attend my friend's wedding. I will be taking the American Airline and transiting through Miami while going to Lima and Dallas while coming back to Toronto. My transit time is 1.5 to 2 hours. Previously, I have traveled to USA for the first time from Buffalo via Niagara Border last October. I have a B2 visa and a valid I-192 card.
My questions are:
I know I have to go through Border security at Miami when I arrive to connect my fight to Lima but will I have go through it again in Dallas while going back to Toronto? My concern is the layover time, which is so short and immigration lines could be huge.
Is there a facility for luggage transfer or I have reclaim it at both the stopovers? My airline is same throughout. Don't want to miss flights.
Finally can I return my I-192 when leaving Dallas to Toronto? Just for my own convenience? They ask you to post it or hand it over and since I will be in USA, I might as well return it.