Druid/Warlock
In advance I have to say that I didn't test this in rofl ,but I probably will tomorrow.
First and foremost: Sandstorm (1490763): As mentioned many times before, this skill does absolutly no damage (even with 20 points of Nature) and consumes, contrary to it's description, 5 Points of Nature. On any other Druid, and at least in the german translation of this skill, Sandstorm should consume 1 Point of Nature to enhance Sandstorms damage, but it consumes 1 per tick ( So 5 in total). It makes no sense to use a skill that a) doesn't do any damage and b) costs you 5% Poison damage and 5% magical damage.
To the damage of this class overall I have 2 ideas.
1) Also mentioned from different people above the only "buff" you can activly use this class has is Body Vitalization. So I suggest that Unity with mother Earth, instead of 10% healing increase, instead increases the magical damage or poison damage of this class. Also I think that Savage Blessing should increase your magical damage (e.g. as it increases HP on Champ/Druid) because although you have much magical attack points your magical damage is rather low.
2) Give the skills of this class a cast speed scaling as you did with Scout/Warlock. This would increase the damage of almost every skill greatly.
Another point is that "Earth Arrow"(1490762) as well as "Psychic Arrows"(1490760) have no use on this class at the moment because "Poison Arrow"(1490621) (not sure if this is the correct name :D, with 0 Points of Nature deals more damage than the other 2 with 20 points of Nature.
Lastly, although I hope this will be solved with the new world boss, I hope in the future there will be a talisman with elemental damage, but even without the elemental damage any talisman would benefit my second suggestion since you can use an additional "curse"-rune.
Anyway, these are just my opinions on this class.
Greetings.