Just because other MMOs let people fight with farming tools doesn't make them good weapons. The whole reason people ever use them is due to this iconography with the grim reaper- and the grim reaper uses a scythe because it is the "harvester of souls". The entire reason it uses a scythe is because it's a farming tool- and he's the farmer. In an actual fight, a scythe is terrible, as I explained earlier. You can justify other MMOs letting you use scythes, or other classes using comically unwieldy weapons(Yes yes, the astrologian duel disk is silly, I agree), but it doesn't make the idea of fighting with a farming tool any better! Just because other ideas are bad does not mean bad ideas should be perpetrated- strive to be better, not be "As good".
In terms of this class, if I may- if you want a sort of holy DPS with a similar weapon type, how about "Templar" or "Crusader"? Heck, one could be a class and the other a job if you like that format. Both are holy warriors(and the paladin fluff isn't... terribly close in retrospect), and at least templars have some history in Final Fantasy(Specifically, FFTA(Maybe just FFTA2? I'm not looking it up)). You could give them say... halberds, glaives, bec-de-corbins, and the like, and it would fit well. They could even keep the same attack styles and things like "Divinity" and "Creed" and holy magic, and it would all still fit in place.