Highest scope zoom is 8x for destiny. Range finders are useless when you've put in a lot of hours as a sniper and learning maps. And zeroing is super easy like you said, but that's actually a real life sniper mechanic. Now I can't remember where I exactly got this info, but "zeroing" IRL, is something along the lines of changing the angle of your scope ever so slightly to help you deal with longer range targets.