Heavy pulls will not go very high at all - in fact, you will usually be wondering how you could have ever possible snatched or cleaned that weight before.
Yes, coming up onto your toes is fine, just don't over-emphasize it. It's not meant to be a calf raise, but extending the ankles is a natural part of the movement.
Pulls should be just focused on a complete extension of the body - worry about your body position rather than the height of the bar. No arm bend in pulls, although you can break the elbows a bit and guide them out to give the bar somewhere to go besides forward if you've put a lot of speed on it. High-pulls will have you trying to get your elbows up as high as you can.
Yes, use straps. Usually without straps, grip insecurity will limit how much speed you can put on the bar.