you posted a lot there to try an convince us. it is a fail imo.
see here.
http://en.wikipedia.org/wiki/Nap-of-the-earth
If you are on a map that has some mountains, this is how you hide your dot from low flying enemy fighters in the distance. if it is a flat map, you get to the treeline at ~ 100 meters to blend in. if you are over water, you go low, but not so low to make a wake and be seen. it is part of defensive flying to get to the target area and make your low level ground attack without being seen and coming in from an unexpected direction. this is especially important for the solo bomber. given the expectations of this sim, fixing the flying through trees should be high on the list of things to fix because it turns the challenge into arcade.