Build isn't really that great.
-Entangling shot, redundant as you have caltrops in your build, not worth the loss of devouring arrow for the extra hatred regen, either.
-Battle Scars prep rune, useless in inferno in any act other than act 1 unless you're rolling some high survivability build that you wont kill anything with. Given you get one shot. Also makes kiting for long periods impossible when you run out of discipline. Focused mind clearly superior.
-Thrill of the hunt, Anything more than caltrops is redundant unless you're against fast mobs, but in this case it's either a skip or burn down fast with a wall of immobilize traps.
-Impale, i find this only useful for mobile bosses that constantly move all over. But even then it's better to use Devouring arrow when they move to pool up hatred for NT spam when they stop.
-Lingering fog rune, really doesn't help much to the duration of the smoke screen. If you're basing it off the tooltip, then it's wrong. 35% movement speed would be a better choice to get away faster to place more traps and thus plant faster to do more damage.
I don't neccesarily agree. The build is actually pretty good. In D3 i have learned not to judge a build by the cover. You should try it out before you judge. It isn't bad actually. Although you make some valid points and the build can be made better, it is still pretty good. I agree with you about the passives though, it is not the best set of passives.
yes entangling shot is redundant since it does not stack with caltrops but that is not the point, the extra hatred is so that you can SPAM Elemental arrow (Lightning or NT) for tons of AOE damage. Despite the fact that it doesn't stack with caltrops, it is still helpful for some targets that the caltrops can't get. As you already pointed out some bosses go all over the place - this is where entangling shots come into play as well.
-Battle Scars prep rune, this I think is a must have for demon hunters. especially since smokescreen got nerfed and we have very little defensive skills. I can't tell you how many times this has saved me.
-As for impale, I think it is meant as like an occasional use, i keep it on the last slot to use occasionally. Because with entangling shot's hatred regen and the low cost of elemental arrow, this should be used only in specific scenarios.
--Lingering fog is also debatable. since they nerfed it, even the minimal time boost can be somewhat helpful. but the movement speed is also a good option. I think either will suffice, they are almost the same if you think about it.
*EDIT* also, care to share your build?