1. I usually put my climber around 15ft. my one ladderstand is closer to 20ft
2. that's about the average around here
3. I don't know if I've ever seen a stand that was much over 20', if at all
4. Southern Illinois

If its of any interest to you or your company I think the biggest advantage to a treestand isn't the winding or "out of view" aspect but the fact that YOU can see better. Not that the deer can see you less.