Does preforming heavy squats also work the traps?
Heavy squats are the King of all exercises. This means that they literally put strain on almost the entire body. So yes, they would work the traps as well. Check out the book Super Squats or Dinosaur Training for more on this, and how great this exercise truly is.
all depends on how you're holding the weight I suppose, but assuming you're talking about back squats...no
