That's probably the most strained bit of folk etymology I've ever run across. The "f" word goes much further back than even the Greeks and Romans, deriving from a Sanskrit root which meant something like "shrivel up and die" without necessarily having a sexual context. Some form of gesture to accompany the expletive is common; in Italy it's a closed fist with the tip of the thumb projecting between the index and second fingers, In England, the erect middle finger is used occasionally but more commonly the first and second fingers are held up spread in a "V" (with the back of the hand forward, as opposed to Chuchill's "V for victory").

By the way, the English bowman's arrows were fletched with goose, not pheasant, feathers. Also, I don't think that the Greeks, and the Romans, were all that much opposed to homosexual practices; read Homer.