Get rid of Dragon Leap, that has no use in PvE, replace it with Standard of Might, on DW bar get rid of Steel Tornado and replace it with Rearming Trap, and also replace Bloodthirst with the Psijic spammable. Blood Spawn monster set is useless in PvE so i'd look into replacing it with Velidreth. Go farm nCR for Relequen body pieces, it provides excellent single target dps. Make sure you always run 7 medium, and use Weapon Power pots on dummy if you haven't already.

What @Joker99 said, with one big disagreement: Rending Slashes over Psijic on the DW bar. The Psijic skill (believe its Crushing Weapon) costs too much. With the last update, Rending Slashes is the closest thing DKs have to a spammable.

Smaller things: would start the rotation with Flames of Oblivion and mix in a light attack between your 3 bow skills. If you want to run a AOE like attack on your DW bar, Shrouded Daggers is a decent swap for Steel Tornado (in places like BRP or other fights with a lot of adds with the boss). Is "Stam Breath" Noxious Breath? If so, good. If not, make it Noxious Breath.

Velidreth is the toughest monster set helmet to get for stamina builds, especially in the weight and trait. Stormfist is probably the easiest, plus it is great for sustain. I'd get that first, then work on Velidreth. Selene's used to be BiS. Not anymore, but serviceable and easy to acquire. Get trials gear, but you know that. Other non-trials gear to consider is swapping Briarheart for Hundlings. Its a choice between guaranteed weapon damage and the chance to proc better weapon damage. Haven't run it, but a lot of people like it.

Finally, what food are you running? I run Dubious Camoran Throne for most dungeons and trials, and a blue food for health and stamina for overland content. A Psijic food is the best, just can't remember the name of it now. Either way, it requires some difficult/expensive to obtain ingredients. DCT is easier to craft. Has a substantial effect on your damage dealing.