1) If it is available after a crit hit (ranged) why not just make it a passive ability? Now, if I read right, they took out the cool down timer on it? Why make us clicky every time we crit. With a whooping 12% crit rate + talents, my finger is going to fall off =P
When I first read about the Kill Command I thought it was for the pet. I didn't realize it was a hotkey I had to press myself after a Crit. Needless to say, I fell in love with the ability as soon as I got it though. The added damage counts toward aggro for your pet, and it doesn't take up any of their focus (energy) at all. It only takes a small amount of mana from you instead.
With full sunders on I've easily had my pet crit for up to 1200+ if not more with Kill Command.
2) How come so late in the game? Oh the 10-65 levels would have been much nicer with that, and not to mention it's a talent on tier 2 for our BM tree. Little did I know 65 levels later that talent(s) will actually do more than give me 2% attack power.
I would have loved to have this command earlier. Perhaps different ranks of it. Obviously at level 66 it will add an additional 127 damage to your pet's normal damage, but early on perhaps they could have added it around lvl 15 or 20 to add maybe 20 damage. Then again at lvl 30 to add 40 damage, and so on until they reach lvl 66 or so.
My only problem sometimes is remembering to press it. I'm not sure if it's part of Blizzard's UI or my own, but a giant message saying "KILL COMMAND" will pop up on my screen after I crit, telling me to press the button basically. Well it doesn't always pop up and sometimes when it does, I can't exactly press it cause I might be running, or kiting at the time ;)
Just make sure your pet is always within range and you're fine. Great addition for us hunters though, just wish we would have had this sooner.