I am all for any system that rewards time and effort spent with something tangible and not just a simple "oh well, you didn't get your drop this week, try again next week!" because I would probably burn out very quickly.

The game already gives you the option of gearing up alt jobs on a class other than the one you have at 50, or are even using in the dungeons at the time, so the only way to make this at all compatible would be to add tokens to fights, or make EVERYTHING purchasable with some kind of currency like Tomes and Marks. And even then they would just cap, to which point people would complain about the caps.