She met with the Avengers in the Captain Marvel post-credit scene. Rocket was there and presumably had a tracker on his ship.
The van was there for five years, something was bound to happen to it one day.Rat. Like come one.
The rest are contrivances (except for Banner, which is just not explained in detail) but like who cares? If movies didn't have plot contrivances they wouldn't be movies. None of the contrivances break any of the characters or ruin the story.