#11 - it's not about what they'll tell you when you get in the country! Airlines are now required to make sure each traveler has also necessary requirements/documents for the country they're flying into at check-in before being allowed to board the plane.
Not sure how you may be getting around this, but perhaps tell what country you're from and what airline you're flying. I know it's already been stated IF they ask for proof, but I always fly AA and am fairly certain everything the agent needs to know/ask pops up on the computer at check-in.
The More I Go...The Less I Know ~
2019: Puerto Rico, Costa Rica, El Salvador, NYC, Croatia, Montenegro, Bosnia & Herzegovina, Istanbul, American Southwest Grand Circle, Los Angeles, Brazil/Peru Amazonas, Colombia.
The Ozarks and Buffalo National River area keep me occupied while home.