Isn't this just... normal? Maybe they use it more often, but (also in the Midwest as other comments mention) these uses are all more common than an actual apology.
But for a more distant example of the "I'm about to inconvenience you" usage being normal - isn't the Japanese "sumimasen" used almost exactly the same as these?
But for a more distant example of the "I'm about to inconvenience you" usage being normal - isn't the Japanese "sumimasen" used almost exactly the same as these?