Given a travel related situation, and given a specific question about the situation, summarize the question into a title

Q: I am a US passport holder (living in Canada) traveling from Canada to Ecuador with connections in the US via multiple airlines. I'm worried that some of my layovers might be a bit too tight. To help plan, I'm trying to find out when, where, and how many times I'll have to check luggage and have security checks.

This was all purchased on a single ticket through Cheap O Air.

Here's my itinerary: 

Edmonton, Canada (YEG) -> Las Vegas, USA (LAS) Airline: WestJet
Departure: 8:30 AM, Arrival: 10:30 AM

-Layover time: 1:48-

Las Vegas, USA -> Miami, USA (MIA) Airline: American Airlines
Departure: 12:18 PM, Arrival: 8:07 PM

-Layover time: 1:23-

Miami, USA -> Quito, Ecuador (UIO) Airline: LATAM Airlines
Departure: 9:30PM, Arrival: 12:45Am (next day)

Questions:

Will I have to baggage check for each airline? And does that mean I have to leave the gates for each check and do security each time? If not, where and when can I expect those things to happen?

Also, I did an online chat with a Cheap O Air representative, and the he assured me that I would only need to do baggage check and security at YEG and not at my connections in the US. That sounds too good to be true to be honest and I don't know if I believe him.


A: Canada to South America with connections in US with multiple airlines, where will I do security/baggage check?
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Q: I have 2h40 between two international flights at Ministro Pistarini Airport, in Buenos Aires. Am I screwed?

Coming from Santiago and going to Brazil, both flights are in Terminal A.

The tickets are from different companies (coming with Qantas via LAN, going with United via Turkish).


A: Time between flights in Ministro Pistarini Airport (Buenos Aires)
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Q: Are only Catholics/Christians allowed to visit the Vatican?

If not, can the non-Catholics access the same areas as Catholics?


A:
Do I have to be Catholic to visit the Vatican City?
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