Jishnu's Radiance: The ws has scaled poorly from what it was at 85 and for a multi-hit+crit ws, it really falls behind other ranged ws. It is also frowned upon due to its dex mod (when ranged attacks are agi based) but if the fTP was increased slightly then this would help counteract this.
WTF this makes no sense. JR is as powerful as / nearly as (depending on gear and situation) LS for physical ranged WS. WF is highly reliant on some sort of +Fire Damage buff typically seen inside abyssea or voidwatch, it's also magic damage so favors COR by far. Ranged attacks are not "AGI Based", AGI only effects ranged accuracy and RNG has an A+ skill along with five accuracy bonus traits for a total of +60. If anything Ranged Attacks are "STR based" as they get double the fSTR bonus that melees get. The only reason you see more Marks Rangers is that they have more options (Anni / Arma) where as Gandiva is JR spam RNG only, both deal the same amount of damage but Marks has the choice of switching to magic or reduced-hate damage.