Originally Posted by
CPH-Flyer
1 and 3.
For 1, it also applies to flights operated by non OW airlines. E.g. Bangkok Airways with JL flight number, or Emirates with JL flight number.
... which is the opposite how Star works, so have to be careful. On the upside, as long as your ticket is sold by JAL (and all flights are JL), you can get some pretty good JL metal FOPs far beyond where JL reaches out to - something like SYD SIN NRT would work if your QF flight was with a JL number, which is pretty cool.