I have played a Fire/Traps Corrupter with a group of people also playing /Traps Corrupters and it has to be one of the most fun synergies out there. FFG stacks SOOOOOOO nice, making everyone untouchable as we slaughter.
One thing we all did to make our AOE very effective was slot damage proc IO's into our Poison Trap. There are two available around lvl 20; both are Holds I believe. I really really really really suggest you slot those two into poison trap. and the rest Recharge. It will make you kill much faster; I can drop an entire group to half health with just my two Psi Proc IO's in Poison Trap; but I have to get lucky and have them both hit....
Its defiantly worth the inf for the price of them.
