Lil help for nub
About your equip, in pve actually the only thing that matter is kill fast, expecially if you’re a warrior (the “best” dps class in PvE). You can use Berserker trinkets and deal high damage without problems. In the 90% of the dps builds you need berserker trinkets. Also in www builds there’s berserker trinkets, to help deal some damage.
The Infusion can be a Offensive and you can put Power. With 5 trinkets+back you can obtain 30 power, and it’s good. If you put power in all your equip (trinket, back, armor and weapons) you can obtain70 of Power and that’s like another berserker ring.
About your runes, Melandru is a Defensive rune. If you use the GS you need Offensive runes like Strength, Pack, Eagle, or Ogre. And to obtain all the effect of the Rune you need to use 6 of them, one for every piece of armor.
About your Sigils, you can use something like superior sigil of Bloodlust that give you Power stacks (25 power stacks is like 250 power, very good for a dps class) and the superior sigil of Air (or Fire) that grant you an additional attack every X seconds on your critical hits.
With a warrior in pve you can focus everything on your damage (and if you want you can use something like a Walkyrie armor to obtain a lot of Vitality, to not die quickly against a big boss)
Everything Silv said.
This will tell you pretty much everything you need to know
As for open world, you don’t really need to run both banners. I usually run For Great Justice/Signet of Fury/Banner of Discipline.
As to what Silv said, Warrior is no where near the best DPS in PvE. Easily outclassed by classes like Ele and Thief, but they’re great at buffing the group