Hmm, I'll watch Dualgunner's video when I get home.

Are you having high ping constantly?

Because that's what killed my GCD/Weaving part .

Also yes, basically what others have said, you need to keep the GCDs rolling and always rolling unless mechanics tell you not to.
GSK optimization comes second, as the DPS increase from utilizing 3 GSK per minute isn't on par with optimizing the GCDs rotation.