Well I use that Addon that Shows Internal Coooldowns I use more Arcane Shots until they proc the Bonus, in T13 it was extra Haste and in T15 it's an additional shot, then I do normal Rotation, and when the internal CD has cooled down I use more Arcane Shots again.
And what about the "your dire beast can be killed" Argument? Hunters are a Class that autoattacks and also have a Pet that attacks aswell; so if a Caster uses 1 GCD Spell (of 1.5 Seconds) to kill your beast that you summoned with 1sec GCD while also autoattacking and having your normal pet attack I think it's a success. I Switch Talents and Glyphs a lot for PvP and dire Beast can be really great at times. However, on higher Ratings the GCD consumption starts to hurt if used during the 1000 PvP Power Set proc, and the beast can get kited which diminishes ist effectiveness.