OED's earliest citation for the verb fly (literally, move through the air with wings) is Beowulf...
Nacod niðdraca, nihtes fleogeð fyre befangen
(I assume I've highlighted the right word; I'm not good at English that old! :)
A few centuries later (certainly by C13 Chaucer) they report the word being used "figuratively", as...
(esp. of fame, a report, etc.)
to fly high (or a high pitch) : to aim at or reach a high pitch of action, feeling, etc.
to fly low : to avoid notoriety.
A centuries or two after that, OED has citations where it defines (again, figurative) fly as...
To move or travel swiftly, pass rapidly, rush along.
After another century or two, we finally reach OP's specific usage (this from Wikipedia)...
The first reference in print to [The Flying Dutchman] appears in Chapter VI of A Voyage to Botany Bay (1795) (also known as A Voyage to New South Wales), attributed to George Barrington.
My guess would be that Barrington (or whatever sailors he may have gotten the yarn from) probably intended both senses 2 and 3 above (but not 1, presumably).
Wikipedia's suggestion that the ship appeared to literally fly, float aloft because of an optical illusion caused by atmospherics is unlikely, to say the least. If that was the original meaning, Barrington would surely have mentioned it, since ships don't normally float in the air.
As regards OP's idea that to fly might be used to mean to roam, drift - the short answer is No! There are lots of other ways the word can be used (if you don't know them, look in a dictionary). About the closest to OP's roaming context is fly = flee, escape, leave [hurriedly].
Up in the Air just happens to be a movie about a guy who spends a lot of time in planes (flying from city to city for his job). It's got no real relevance to OP's context.