I have put a footer behind the lifetime status for all three status levels for JGC Crystal to clarify it.
Yep, you are right about JAL being convoluted with some sort of side level you could only reach after you have qualified for a certain regular level.
Anyway, the combination of points / miles or kilometres at oneworld make things not easier, esp. since the number of pts vary betw. the airlines concerning how many you earn (fixe number at BA, according to flewn mls at QF, a combination of both ...)