When the suit blows out all support will suddenly be lost. This could possibly cause you to completely lose control of the bar and even fall with the weight. The chance of injury is not worth the price of a new suit. The closer the lifter is to the floor, the less distance the bar must be pulled. Thus, less total work and possibly more weight lifted.
Many lifters prefer to deadlift in their socks or a thin slipper.
Neither of these two provide very much traction. It is very possible that the lifter may slip. Another popular shoe is the wrestling shoe. The wrestling shoe has a very thin sole, has good traction, and also provides ankle support. In my opinion this is the better choice of foot apparel.