Thats an awful lot of volume in one day. I know in the CFT article Rip talks about a warm-up for the CFT lifts (of which the deadlift is one) then go for 1 heavy pull. I think you'd get more benefit out of this. My guess is your deadlift for a bunch of reps isn't as deadlift as you think. The bar must be on the ground not moving, and no stretch reflex is to be involved. Too many people I see that are doing multiple reps don't put the bar down and let it be without motion. This is essential for a good deadlift set.
If you do the deadlift correctly the result isn't a chance of injury, its a chance of getting stronger.