, you are a worrier! If I ever had to leave my horses with someone I would like to find a person just like you.
Growing up on a dairy farm, we had barbed wire, and over period of two decades we had a couple of horses get tangled in it. Awful stuff, and I cringe when I see horses in a barbed wire fence.
My brother-in-law runs over a hundred head of Angus cattle, and he uses five strands of high tensile smooth wire, electrified. When my niece got her first mustang, after it had calmed down she let it out into a slightly larger enclosure in front of the barn. While nobody was around, the horse took a run at the fence. I would have guessed that a horse running into wire like that would get sliced up like a hard boiled egg, but that mustang didn't have a mark on it. Instead it was upside down and dead as a doornail. It apparently bounced back with such force that it flipped over backwards and smacked its head on the frozen ground. BLM guys said, "well, not much you could have done about that." Her second mustang is her forever trail horse.
When I first got my horse I bought wooden posts. I had one in the ground as part of a divider fence. One night when I didn't have any fencing up my big guy ran right into the post and snapped it off at the ground.
When he was a yearling I was boarding two other yearlings and one snowy morning all three of them came barrelling around the corner and one by one their legs went out from under them and they all slid more than 50 feet. No harm done.
I bought some cattle net from Premier and was using it to move my Scottish Highland heifers around to clean up the grass in different areas. Worked fine for about a week. One day they were eating happily one minute, and the next time we looked there were no cows and no fence! I found them out in the corn field and one of the heifers was still wearing the fence. That netting doesn't work with cows with long horns.
I live on a state highway, and in the early days my horses got out more than once. One day a neighbor across the road noticed my big guy out and grabbed an extension cord and walked over and used it to lead him to the round pen, where I found him when I got home.
I am a big fan of steel t-posts. Used ones are cheap, they're easy to drive, they're easy to move, and they're very strong. I cap them with Red Snap'r® t-post caps, which eliminates the chance of a horse coming down and impaling himself on one. I buy the t-posts used at auction or from Craigslist for around $2 each, and put them in 25' apart. An alternative would be the thick fiberglass Pasture Pro posts from PasturePro 1 1/2" x 72" ProLine PLUS Fence Post - ruralmfg.com
, but at almost $10 each that would get expensive.
I think Electrobraid is an excellent system. I use Premier's Intellibraid, which has equal strength but all the copper conductor wires are tinned for corrosion resistance. That somewhat simplifies connections to the energizer, ground rods, and any place you need a jumper wire.