Have just revisited this thread, after several days’ absence – can’t resist adding my two British pence. caniswalensis, sorry if what I contribute here, annoys...
“Expression drift” which forces changing of meaning of words, as opposed to otherwise – really not much of a problem for me – I being mostly of the wet-liberal “language is a democracy” persuasion.
In the rare instances of my using “ji*es with” (=agrees with, meshes-in with), I use “jibe”. On the rare occasions when I’ve encountered the expression from others “in real life”, I think “jibe” has been used, not “jive”. (I’m in the UK, for what that may be worth.) Have often seen, on the Internet in recent years, “jive” used in this context. As above – am personally a tolerance-merchant, inclined to feel, “I grok what people are trying to get at, what the heck...” Can see some of the point, of others with a more rigorous prescriptivist view...
Staying out of the “gybe” / nautical arena. Sailing / ship-handling stuff is total black magic, so far as I’m concerned.
The “could care less / couldn’t care less” thing. In my experience in the UK, “couldn’t care less” is invariably used here; other side of the Atlantic, it’s often “could care less”. Submitting a thought which I don’t think has hitherto come up on this thread (I may be wrong) – I can see logical justification for both forms of the expression. “I couldn’t care less”: there is no way I could be less interested than I am, in this stuff. “I could care less”: I suppose it’s JUST possible that I could have more-than-zero interest in this stuff, but don’t bet on it.
http://forum.wordreference.com/forumdisplay.php?f=6 -- dedicated to the minutiae of English-language usage, and the analysing of same -- has a several-pages-long thread on “I couldn’t care less / I could care less”, with no firm verdict the one versus t’other, being arrived at – general feeling that “I could care less” is the less obviously sense-making, but “not totally” – and, making strict sense not necessarily be-all-and-end-all.