Lol that's funny walkamile. My old horse spirit got the scare of her life on a ride. We stopped by a pond to eat and rest and my horse screamed, I looked and she was bein chaced by .........a.......BABY DUCK!!!! Lol it was so funny!
My Hoover is half standy, and I love the breed because of him. He was an awesome trail boy before his ankles got worse, gave me the best of himself and was so proud and happy to have "our" time out in the woods. When you tacked him up and started the trail, he would dance like an Arabian, like he was showing off to the herd that he was having "Mommy time" and they weren't.
I eventually want to get an OTSTB to start some short endurance. My next horse, I can't afford more than two right now.
Standardbreds can make great trail mounts, but it depends on the individual horse. I'd say take him in small distances first and see how he does, be calm and don't even think about it. As he gets acclimated to it, go out for longer trails and look for more challenging terrain.
My duaghters horse is a standard. Buddy came to us off an Amish farm and had never seen trails or had never been cared for by a loving 9 year old. (amish generally don't pet there horses). After about 6 months he is so attached to my duaghter that she doesn't even have to use a leed rope. He just followers her everywhere.
We took it slow with him at first on the tails, he wasn't used to rough terran so he stumbled a lot. Now he can go anywhere.