Traps
Must Have:
Acid Mortar
FFG
Seekers
PGT + PvE Stealth
Good:
Caltrops
Trip Mine
Webby
Don't Bother:
Time Bomb
You break the Alpha with seekers, lock them down with PGT, Debuff with Mortar, ... Then blow them up any way you like.
Alternately, Drop Caltrops between you and them, drop PGT, optional Trip Mine, Drop Mortar .. The mortar annoys them, and when they come for you the Caltrops and PGT lock them in the killing field.
I pretty much agree with Linea_Alba except for the PvE stealth bit. PvE stealth is useful on a trapper but is hardly essential. I dropped it on my trapper in favor of an extra leadership power since I find I'm tough enough to go in and toe bomb even if they can see me but YMMV.
Man, my search fu sucks....
Anyways, anyone got a rundown of which Traps powers should be taken the instant they come up, which can be put off a while to get some stuff from your secondary, Fitness, and travel, which should be left 'til late, and which should just not be bothered with? (as an MM secondary it was easy...)