Here is the part I tell you something amazing: Most of those fancy WHM robes really have nothing to do with White Mages (in FFXIV)! (Aside from the lv50 stuff. Yes, you did dig up a dead guy's robes that had been spread around the country). That fancy i90 robe? Rowena made 'em. All the other gear you've gotten from her? Basically crafted. So...yes, it might require the job crystal to equip because of game mechanics, but that's simply glamour and battle mechanics. Replicas of "legendary" or "artifact" equipment is [while yes, maybe rare for poor people or nonadventurers] common enough for people to have!
You've nothing to apologize for! Look the way to want to. ...now if you start casting White Magic, the lore hounds may OOCly question how. (but looking at the skills, the Battle Team at SE has made skills inconsistent all over. Why are Cure 2 and Aero 3 somehow Succor but the rest aren't?!)
Little edit: The colors of the CNJ robes are actually their rank. So I guess one levels from boring potato sack to shiny potato sack. :p