I'm sure your team has plans in the works, and are already working on multiple classes and jobs to roll out in the future. However I think I may have a suggestion that will tickle your Final Fantasy fancy; gunblade and thief sword class!
Think Zidane from FF IX, maybe a thief class, dual daggers or the iconic double bladed thief swords. And the Garlean with their technology, and there already existing gunblades there, is the perfect steep to a gunblade wielding class!
I hope you take a serious look at this and leave me even the smallest teaser