You don't NEED to do a FP for anything at Disney.
FP for RoL is a lot like a FP for Fantasmic..you can choose to sit in that section if you want, but you'll still want to get there with plenty of time left or you run the risk of the section filling.
I personally find the FP area to be the most "centered" section for the show, but no section is bad.
Just like Fantasmic, whether you do dining package, FP, or standby, I'd recommend getting there at least 45 min ahead of showtime.