DRK Rotation Help?

[Phoenicia]

Honestly it's hard to tell exactly without logs or a video of you doing said rotation.

Food and pots do make a difference. If those videos have a slashing debuff up, that's what's you're missing as you do get ~10% increase.

Only other thing I can point out is that that rotation is a double weave rotation, so if your skill speed or your ping is too high you might be clipping your GCD and as such losing DPS. Either try a lower speed or check out the high speed/ping friendly rotations like this one: http://ffxivrotations.com/1tbk