There is no way to pinpoint whether you are proficient in your job or if you only think you are doing good. At least the game does not provide any meaningful tools for it.
One of my biggest challenges when playing dancer was to hit and do 8/9 GCDS during the burst window, because sometimes clipping meant I would miss at least one. For you would be during the Brotherhood window.
Other things to consider, buffs always kept up, hitting your positional at all times, and not canceling combos.