The rack deadlift is great for lifters with less range of motion, but can also be used to work the top range of the deadlift with a heavier load.
Typically, the rack deadlift is set up with the bar just below the knees, but just above the knee is fine too. If you don't have a rack, use a few 45 pound Olympic plates to elevate the bar into position.
The first rule of fixing your bench press is admitting your bench sucks. The second rule is that you must read this article and learn about the set-up, grip, ascent, and descent.