Fire, I'm just pulling a Copy Pasta of the message I sent you, so that others can reflect off of what I mentioned, and possibly help out:
I gave it a read and there are few iffy' things that I noticed.
First, at 16th level the Sniper no longer has to worry about range increments and can fire at any target in line of sight. This is the Epic Feat "Distance Shot". Now, Distance Shot has the prerequisites of Dex 25, Far Shot, Point Blank Shot, and Spot 20 ranks. I don't know if you really want to give a class an epic feat at 16th. 20th maybe, but 16th?
Speaking of 20th, that's not just an epic feat too it's actually BETTER! Swarm of Arrows lets you rain down doom at your base attack bonus to every enemy in 30 feet as a full action.
I looked at this class, and while it's a sniper, and has lots of movement and hiding and what not, it has no Save or Die ability. Why not give them the Pathfinder Ranger 20th level ability of "Once Per Day, an arrow you fire is an Arrow of Slaying." deal. A 20th level sniper should be able to literally just command someone to die by twanging an arrow, or whatever sound effect arrows make.
Okay, so Light Step. It's WIS mod / day or Class Level / Day... which means after fifth level, it's Class Level / Day. Why not pick one
Either make it Wisdom Mod / Day for each of them (Because if you need to cast Water Walk more then 3 times a day, something is terribly wrong), or just let them do it whenever they want after 10th level. Since you'll be using your class level as the caster level (Which you didn't mention but I assumed), most of these will last long enough to get you either to a great vantage point (In the cases of Spider Climb and Water Walk)... or to Valhalla (In the case of Air Walk).
Now, ShotWalk. It sounds really interesting, but the ultimate question is Why? I'm a Sniper. I have a spot, and I'm not leaving it. Now, if I'm discovered and people are trying to kill me, then I can use the ability to fire at anything I can see to shoot the horizon and leave combat 11 miles behind me. Sure, that's handy. But there's no way I'm going to teleport within 30 feet of the guy I just shot. He's probably either dead, or super-pissed off.
What you may want to consider are things like "You can scry on the location of anywhere your shots hit" or something like that. Perhaps also include a class feature that says "Non-magical arrows and bolts that you fire that miss don't ever break" and then later on "Magical arrows and bolts you fire that miss only break 50% of the time" to let snipers recover arrows better. Also account for folks taking levels in Sniper that aren't using a bow (Since it isn't a pre-requisite). You could take this class with someone who throws axes or javelins. Or small countries (See "Hulking Hurler" for details).
Cause you know someone on this board will class into Sniper from HH and when they're discovered, they'll throw the tree they're hiding in at someone.
Other then that, I think this is cool. I like the trick shots! Though, a few of them replace feats. Will they replace the feat for the purposes of qualifying for stuff as well. I know Ranged Disarm is a feat, for instance.