A: Actually I think you’ll find it’s “metric fuck-tonne” in Australia. Or just “fuck-tonne”.
A “fuckton” is not only an Imperial US unit of fucks, but it is smaller than the metric fuck-tonne, which is exactly 1,000kg of fucks.
The simple experiment of weighing someone before and after expressing a fuck tells us that there are a large number of fucks per kilogram.
But since the saying “fuck-tonne” is meant to describe an extremely large number of fucks, it seems to make sense to use the metric tonne and not the Imperial ton.
There’s no rule to say you must hyphenate it to “fuck-tonne” rather than “fucktonne” or “fuckton.”
However if you hyphenate it, you reduce the risk that the reader will think you’re referring to a place (rather than a quantity) of fucks.
In some US states it only takes a majority vote in the town to change the town’s name. There’s nowhere called Fuckton in the US yet but there’s already an Effington in Minnesota. So it’s only a matter of time.