Someone has brought this up before, but I can't see it in the top page, and it bears repeating with the introduction of a relevant dev tag.
It would just be nice if abilities would appear grayed out when out of range or a battle context, like evade, parry, or block, is not met. This already occurs if a player has insufficient HP, MP, or TP to use an ability. This would help classes position themselves at the optimal range in party play and facilitate the use of abilities like Feint, Phalanx, Fracture, and Haymaker by providing information in an intuitive way.