I will take a guess and say "Shoot it low" can refer to two things; 1) the way gun shooters who haven't learned how to control the gun tend to shoot downward. Shoving it forward while firing will shoot downward. 2) an archer's creed is to "aim high, shoot low" taking in account of wind resistance, trajectory, weight, and obstacles. "I shoot it high, let it fly" sounds more arrow than bullet? Due to mentions of trees, shores, rivers, "Kill the flow" can refer to three things: 1) breaking the river's serenity, but the river will return to its natural state. 2) breaking the wild's serenity, but the wild will return to its natural state. 3) wanting to break the mind's operation, which otherwise returns to the person's phone number on the singer's mind. "Ruin myself" and "Caught in a space between my head and my face again" and "Wishing I could make amends" and "Bury my disease" may refer to the same. "Keys to the kingdom" sounds like the keys are the numbers to dial, and the person is the kingdom, in which is gone with the sinking sun, where the singer wants to bury their disease, wants to kill the flow, kill the sound, kill the sun, all by drowning to end their pain. "Between my head and my face" seem like the face is in the reflection of the water, and their fixation is in that short distance.
