Actually BRD and DRG feel pretty similar to me, keep up your normal rotation and use the off-GCD moves like repelling, bloodletter, shadowbind, blunt arrow, flaming arrow in between your action cooldown for max damage. Internal release is a short CD, as is barrage and to a lesser extent blood for blood and Hawk's Eye.

And it's not so much that DRG and BRD deal different types of damage, I think it's actually the same piercing/physical damage. Bard's weapon damage is much lower than the other classes, which I guess is supposed to balance with their mobility. They are mainly sustained damage but don't underestimate their burst