I have a small issue with the Graves reworked passive

So now, are Graves and Kalista the only ones who can miss auto attacks? Because if Graves shoots, and the target dies before his attack makes contact with it, then he loses a round of ammo. So technically, he wasted a round.

Is that ok, since he only has 2 bullets at a time?

And second question, is there a way to decrease the amount of time it takes to reload 2 more bullets? Is attack speed supposed to do the trick? Or will he get reduced reload speed as the game goes on? Like reduction per level?