The macro looks functional to me, but I would recommend against using FS to enter combat (the alt modifier looks great btw)

If you are solo, and it takes a mob 3 seconds to run to you, would you rather:
Flameshock, GCD, Cast LvB, get hit OR Cast Lightningbolt, Flameshock, GCD, Cast LvB?

In the later example, the target is taking the additional damage of the LB during the same duration of the FS LvB rotation. This is why a firemage charges up a Pyroblast while ooc, to front load the damge.