Spotshot = Point Shot. Its use in my build is that if you use Rapid Fire (1.5 AP cost), which is the centerpiece of the build, you have .5 AP left over, which is too few to use on most other abilites, but Point Shot gives you regular damage for .5 AP, at the cost of some accuracy (which later on doesn't matter). Sometimes also you might need to use AP for movement, healing, reloading, etc, so having an ability that can go for less than full attack AP is very useful.
Aimed Shot is a guaranteed crit for when Rapid Fire is on cooldown. So my usual rotation would be Rapid Fire/Point Shot, followed by Aimed shot/Kneecap Shot, and on repeat.