The only part of that fight which is scripted is my soft start on the boss so I don't do real damage until the 4th GCD, at which point a whole lot of big hits happen.
May look chaotic but I know what I'm doing and as you watch I'm doing over 1600dps... while doing all the other things...
You really like that video, don't you…
Most of the DPS in my group are parsing north of 1900 on the dummy, and in the 1700-1800 range on bosses. 1600 is good, but not as impressive as you seem to think. If you used keybinds at all, you might see some improvement.
Assault commando is a fun spec to play though, I don't disagree with that part of it.