1. hmm ? first try reading the manual... press RIGHT MOUSE BUTTON at the circual gray icon in the lower right corner of the weapons picture in you hand, then you can choose where to aim, but if you're fast handed you can not aim. if you want to aim some non-human and know where you are exactly shootin, put yourself in defencive sentrymode and the aim thing on (the circle is yellow) then right click the enemy you wish to aim and shoot at!
2. Well, not by default, but with slayer perk (thou only at lvl24) silent killer, and a good sneak, sure. Otherwise, it might be difficult.
