Casper has the most terrible time on trails. They are like tunnels that he has to shoot through. In our area, trails are typically through dense forest and underbrush, so they are really like tunnels. The people scents go in a straight line, and usually uphill!
If the dog bounces off the end of a long line, then I'd argue the long line isn't much use. In fact, it's more dangerous because it lets the dog get going fast and then bam he hits the end of the leash. Try a shorter long line perhaps?
Some dogs can learn to not get wrapped around trees and poles. Casper is our only one so far, but also the first where we've tried. We have a command, Wrong Way, and that let's him know to go to the other side of the tree. He also knows Back Up to get untangled.
For steep hills and stairs, I've taught Casper to sit and stay at the top. Then I release him, but keep his attention. Then I get him to stop again as needed while going downhill. He has a Stop command, where he stops and sits. If I stop him every few steps, they he can't build up speed.
So, no, we don't go leisurely hiking off into the woods quite yet. Maybe next summer. I ran into a guy hiking with a golden a couple of years ago. That dog was hiking along perfectly. He said the dog was five and it had taken her that long to be really good at hiking.
I don't feel so bad now! I thought I was the only one with a crazy dog when hiking. There's just so many smells he goes crazy. It's kinda cute but I need to practice more with him so it's not so hard on me.