I have successfully used the above ideas quite a few times. I've been just trying to perfect the build, and planned on posting it here. I took my Oath Shot trapping build and modified it slighty, so far I have 2 builds I've been working on.
{note these are all PvE builds, I don't do PvP}
Build #1:
Dis Shot OR Throw Dirt
Whirling Defense
Death's Charge
Dust Trap
Barbed Trap
Flame Trap
Oath Shot
Troll Unguent
With this build, I let the party initiate aggro, while I watch for a nice grouping of enemies from the back lines. Also, I look for good Dis Shot opportunities. As soon as I see a good group of enemies bunched together, OR if I notice a bunch of casters in their back lines hanging around, I hit Whirling Defense and then Death's Charge to their position. I start with Dust, then Barbed, then Flame - the order I have them on the skill bar. The most important of course is Dust, so you can blind them and keep them from interrupting you. (If we have a dedicated interrupter in the party already, sometimes I switch out Dis Shot for Throw Dirt - but I don't like to, really... I rarely leave an outpost without Dis Shot, it's just too handy) Anyway, lay all 3 traps, then Oath Shot. Watch your Whirling Defense, hit it whenever it runs out or is about to. Now, depending on the situation, it's time to either lay more traps, or hit Troll and get back to the back lines to line up another bombing run. Another way to get out of the thick of combat is to look at your radar for an enemy away from the thick of things, then Death's Charge to it. Not only does this get you out of the frying pan, it gets you out of the fire a bit by giving you a small health boost (if that enemy has enough life in him).
Build #2:
Whirling Defense
Death's Charge
Dust Trap
Barbed Trap
Flame Trap
Apply Poison
Oath Shot
Recall
This build is pretty interesting... I was playing around with a 2-man farm team. A protection monk and this build is a lot of fun. Basically, I put Recall on my monk buddy, the prot monk hangs back well out of aggro range and slaps a bunch of protective stuff on me (spellbreaker, mending, protective spirit, Succor, etc.). I then Apply Poison, Whirling Defense, then Death's Charge into combat, and proceed same as build #1. The difference is, when the shit hits the fan, or when I am out of energy, I just cancel the Recall enchant and warp back to my monk buddy, which un-aggroes the mob. Then I start the process over. This build would be incredible I think with 4 trapninjas and 4 protect monks to back them up. All those going in at the same time would be some nasty carnage, and the best part is the monks never even have to engage the enemy.