i would not skip either of those, they both are good powers, especially envenom you really really dont want to skip that, neurotoxic breath i guess is skippable but its one of your few aoe debuffs/controls atm, the massive slow it provides is pretty good along with its natural chance to hold
Neither of those are skippable powers. Poison Trap is merely sleep gas and is generally considered the "always skip" power of the poison set. Also the rez power and the stimulant power could be considered skippable.
How valuable are Envenom and Neurotoxic breath? I'm quite certainly planning to skip them for now, because I don't want my character to do any spitting animations, but I'm thinking that since poison is getting a revamp in i-21, maybe they might fix those.
So, I'm just wondering if it's worth the trouble to save room in the build? I'll probably take poison trap for now to hold a place for one of them (since I know it will be a power I *really* won't mind changing out). I save space for the other, it will probably be late in the build, like around L50.