It's really not that simple.
Corrosive dart is a key part of our rotation to keep our dps high, but if you have the dart up, the flashbang will be broken a second after you throw it, which is why the FB can be difficult to use effectively in 1v1 situations, and instead shines in group combat. We're very reliant on dots, but dots negate our FB.
You can only get the "root" if you spec into it, which means lowering your dps elsewhere, and after 1.2 we really don't have the luxury of further lowering our dps.
Evasion is useful but it lasts four seconds, and thats with the set bonus.
How long does that damage reduction thing you guys have last? Feels like ages.