Like Stormblood, 5.0 will probably usher in at least 2 new buttons per job. To make room for this, I have some suggestions for at least Dragoon (my main job).

1) Remove Heavy Thrust completely and put the Damage+10% buff onto Vorpal Thrust and shorten the buff duration to accommodate this.

2) Remove Impulse Drive and allow for True Thrust to combo into both Vorpal Thrust and Disembowel. Doing this puts Dragoon in-line with other melee:
NIN: Gust Slash combos into Aeolian Edge, Armor Crush, and Shadow Fang
SAM: Hakaze combos into Jinpu, Shifu, and Yukikaze
PLD: Fast Blade combos into Riot Blade and Savage Blade
WAR: Heavy Swing combos into both Skull Sunder and Maim
DRK: Hard Slash combos into both Spinning Slash and Siphon Strike.

This streamlines DRG's combos completely and removes 2 unnecesary abilities and creating room for some new weapon skills.

While we're at it, remove Hot Shot and find some other way to bake it into the kit without 1 button press every 60 seconds