Pg 39 of the BFB (big fat book) says "...models in the second rank can use the line of sight and forward arc of the model directly in front of them for the purposes of all shooting attacks." It says nothing about using their range. Further on, in the "Range of the Weapon" paragraph it says; "A model can normally only shoot at a target if it lies within the maximum range of the weapon it is shooting with."
There is nothing here to say that the second (or third) ranks would use the range of the closer, front rank figures. I have always measured ranges to each individual figure. Many times part of a unit will be in range and part will not. Likewise, often part of the unit will be in close range while part will not be, particularly when using larger, wider units of archers. Some places use "house rules" that give rear ranks the same range as the front rank but this is by no means universal. Your best bet is to measure ranges figure by figure.
I find no BRB FAQs or errata covering this.
There is no problem in the Wood Elven condition that cannot be solved with the appropriate application of a sufficient quantity of Big Amber Spear.