Some suggestions for some magic combinations:
Scout/Warlock
1.
Changed Venomous Snipe to do not provide poison damage any more, increased Snipe damage increment to 24% from 8%. lose its effect when Snipe is used.
My proposicion:
Changed Venomous Snipe to reduce poison damage from 15% to 10% (while excluding this effect on snipe), increased snipe damage increment to 16% from 8%.
2.
Reduced Poisonous Will poison damage gain to 120% from 125%,
since you have to do it (although I honestly don't understand why), in addition Increased Poisonous Surge poison damage gain to 20% from 18%.
3.
Reduced Combo Shot damage from 563% to 467%.
My proposition:
Reduced Combo Shot damage from 563% to 515%.
Warden/Druid
Change the damage scaling to spellcasting speed instead of attack speed and adjust the coefficient as for scout/warlock. This will make more efficient use of your equipment including curse runes.
Warlock/Rouge
Shadow Step - disable the effect of moving behind the target. This will make the skill more effective on this combinations and increase our survivability.