Strafe = ability that is 200% IAS based on your weapon speed. This can stack with Rapid Fire.
Now whether the stack is 50% of 200% for 300%, or if its 50% + 200% for 250% or if its 200% + 50% of base weapons speed for 200% + x%, I couldnt tell you. As for equilibrium, I think its a typo and that should state 300% of weapon speed. (or 3 times weapon speed)