Putting Heavy Thrust's damage bonus on Impulse Drive is fine. Impulse Drive already sounds like it ought to give that buff to begin with, as the name implies that it's giving you an adrenaline boost to improve your strength. It already fits DRG thematically.
I'd much rather see Piercing added to the Ranged DPS than removed entirely, too. Same for adding Slashing to all of the tanks. Those buffs are fine if they all exist on buttons you want to be pressing on your class anyways. Being able to debuff multiple targets at once relatively quickly is also another way to gain DPS in certain situations regarding add phases/multi-dotting and so on mid-fight.
I'd also like to see DRG get a dynamic combo finisher. Basically at any point you could use F&C and WT, you could use it instead to end the combo immediately. After both were used, you'd only have the finisher left. Its potency would increase the same way they do. The 1-2-3-4 buttons can 100% be consolidated down to 2, but adding one more that you can use to end a combo when you want to would help a ton with how DRG plays already, and reward different skill speed breakpoints with different filler options.