RE: How high is too high?
What's too high? Depends on the terrain for me more than anything.
Level ground beneath me and anything over 30 feet is too high.
Add a side hill where I anticipate the shot to happen, 40 feet may not be high enough.
Personally I prefer to stay in the 20 - 25 foot range from my intended target.
I only go higherduring the late season when the cover once afforded by summers leaves have gone.