Just change one word ... "attacks" to "weapons". It's based on the weapon's primary use. Melee items need to hit hard, Ranged ones require accuracy to hit the weak/crit spots.

As for Rogue/Ninja... a DEX mod could be implemented via class/job ability that takes advantage of your DEX along the line of the ARC/BRD ability--temp spikes in crit rate/damage calcs. They'll probably have access to the ARC abilities to that end. Could get traits that mod the boost or cool-down. This could put them in line with traditional setup--lower, steady damage with big spikes from exploiting Crit-Hit mechanics.

If they leave weapon mods on STR because they are melee style weapons and give them abilities for spike damage influenced by DEX/Crit, it would be in keeping with the current system while also paying homage to past mechanics... could be the "happy medium" if implemented well enough.