D&D 5e - Ranger Archetype - Arcane Archer

I really like the Arcane Archer Prestige Class from D&D 3.5e and I wanted to convert an option for it. Decided to build at is a Ranger Archetype because the flavor text to the Arcane Archer made it feel like a Ranger type thing. I have thought about maybe setting it up as a Fighter Archetype instead. Maybe later. But, for now, here is a Ranger version. Also, I didn't like the confusion of just placing spells onto arrows. So instead I just focused on the idea of making imbuing their arrows with fire, lightning, and such. 

Ranger Archetype: Arcane Archer

The Arcane Archer is a warrior skilled in using magic to supplement his combat prowess. Beyond the woods, arcane archers gain renown throughout entire kingdoms for their supernatural accuracy with a bow and their ability to imbue their arrows with magic. In a group, they can strike fear into an entire enemy army.

Enhance Arrows

At 3rd level, you gain the ability to infuse your arrows with arcane magic. Once on each of your turns when you hit a creature with a ranged weapon attack, you can cause the attack to deal an extra 1d8 cold, fire, or lightning damage (your choice) to the target. When you reach 11th level, the extra damage increases to 2d8.

Elemental Shot

At 7th level, you gain the ability to infuse your arrows with overwhelming amounts of energy. As an action, you may choose a point in sight within range of a weapon you are wielding. Any creature within a 20 ft radius of the point must make a Dexterity saving throw against your ranger spell save DC. A target takes 5d6 points of cold, fire, or lightning damage (your choice) to the target on a failed save, or half as much damage on a successful save.

Once you use this feature, you can't use it again until you finish a short or long rest.

Seeking Arrows

Starting at 11th level, your arrows magically seek out your targets, weaving and bobbing around obstacles. Your ranged weapon attacks ignore half cover and three-quarters cover.

Arrow of Death

Starting at 15th level, when you hit a creature a ranged weapon attack, you can use this feature to immediately attempt to slay it. The creature takes an extra 10d10 necrotic damage as necromantic energy charges through their body. 

Once you use this feature, you can't use it again until you finish a long rest.