Garrote is supposedly getting 3 seconds of silence added to its DoT. Silence keeps casters from... well, casting. Not sure it will be that useful even with that added to it though, but I'm going to give it a try none the less. Rogues can Stealth with DoTs on them but they will be brought outta stealth as soon as the damage ticks. If you're fighting another rogue and are not able to stunlock them 100-0, its a good idea to hit em with a rupture so that they can't get away. I use rupture a lot on warriors too along with crip poison. The idea is to get in, get some DoTs on em and get a little ways away from them. The trick is to stay just far enough away so that they can't attack you, but not too far away because they will intercept you if you are. After 5 seconds or so of not being attacked you will be out of combat, you can restealth and do the whole thing over again. As far as off hand weapons, most people say to have as fast an off hand as you can for poison proc'ing reasons, but I don't knowthat it makes all that big a difference.