Back is definitely a bit too rounded, in my opinion. That said, it probably isn't dangerous so long as it remains tight. It also looks closer to a stiff legged deadlift. To clarify, your legs have virtually no bend in them the entire lift. While they are not locked out completely, they are very close. Also, note the slope of your back. It is almost parallel with the ground. This means you are really pulling the weight with your back.
My suggestions:
1) Start with your butt much lower which will allow you to get your torso more upright
2) Focus on not raising your butt immediately starting the lift. Both the knees and hip/back should really be locking out at the same pace and time.
3) Focus on a straighter back.
4) Drop weight just enough to accomplish these things.
On max attempts, it is expected form will crumble a bit. But, if these are just regular work sets, then I would definitely look to implement my suggestions.
Keep in mind, many people successfully deadlift with forms all over the place, even at high levels. But most people should look to implement the cleanest form possible. A good example of clean form would be this:
https://www.youtube.com/watch?v=t6E3GeUisrc
If I had to criticize this guy (which I would not do, since I think his form is great overall) I might suggest he is overarching his back, but difficult to know unless you were able to see an x-ray. On top of that, he has no weight, which makes overarching must easier. Put a load on and most people can't overarch.