Again, it should be noted that they were never going to apply aging makeup on Kes had she stayed til season seven. Ocampa do not "age" in looks until they reach 9. However, "Fury" did make that mistake and made her appear 60, when "Before and After" had firmly established that's not the case.
That's correct. The "writers" didn't even bother to follow their own "canon". It shows how much they cared.
In fact, the whole "Fury" episode was a mistake.
Kes had her second birthday, in season 2s Twisted, which was originally supposed to be aired in season one.
That's also correct.
Kes's birthday takes place between the events in "Elogium", Stardate 48921.3 (Friday 3 December 2371) and "The 37's", Stardate 48975 (Wednesday 22 December 2371). Since "Twisted has no official stardate, I took the liberty to give it Stardate 48961 which would establish Kes's 2nd birthday at 17 December 2371, an appropriate date for "The Day of Kes.