H4M once wrote:
1) Step up to the bar, position your feet. Shins should be damn near touching the bar, if not touching them.
1.5)[optional] Reach upwards with your arms and briefly hyper-extend your back, take a quick breath.
2) Grab the bar, keep your hips nice and high as you adjust grip so as to preserve some elasticity in your muscles before the pull. Really crank your hands into the bar so it doesn't budge and roll around at all.
3) As you bring your hips down to the bar to get them in the pulling position, take a DEEP belly breath, stick your belly as far forward as possible, arch your back HARD.
4) Pull the slack out of the bar, then immediately after doing so, pull the bar BACK, and push your hips forwards once the bar is a few inches off the ground.
Steps 1 and 2 can take 10-30 seconds, that's fine, but steps 3 and 4 should only happen in a 1-2 second time frame. The best way to practice the steps is to treat every warmup set like a max set, as far as setup perfection goes. Don't half-ass warmups, they can be a lifesaver for technique, and making mental notes.
Spread the floor to keep the knees out of the way and pull big boy weights.
The concentric looks ok to me, if anything your shoulders are a little in front of the bar. But your setup and the eccentric takes way too much time and limits what you can lift.
But I only deadlift 463, so take that for what it's worth.