Have any of you tried moving a small house plant via air or mail even? I
guess it's not possible because x-ray machines could damage it or some security
guard will insist on uprooting it and shaking all the dirt out of the roots or
something.

You have been misinformed. There is very little regulation of mailing plants
within the country. Certain states are particular, especially Hawaii, but as
far as I know this applies mainly to commercial greenhouse shipments. I have
stuck orchids in a box & mailed them all over the country by Priority Mail. The
only danger is that in the winter they might freeze & in midsummer they can get
overheated, so it is best to mail them in the spring or fall. They will not be
damaged by X-rays. A private shipment of one houseplant is usually not
inspected, except possibly in California. If you are mailing a plant, you would
take it out of the pot anyway, shake off excess soil, & wrap the roots in
plastic, to avoid excess weight.

Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)