With the price of horses these days, and as hard as it is to find a good one, care and preparation are more important than ever. Without proper care and preparation you aren't going to get that longevity you're looking for from a nice horse, so you'll be in constant search for the next one. Whether you buy a horse or make him yourself, once you get one working the way you want him to it's important to keep him working that way. That means maintenance.
Rope horses need to be ridden outside the arena a lot. They need plenty of exercise, and to be ridden down, because they work better that way. When their minds get to going too fast all the time it takes its toll. I was raised on a ranch, and I had my best horses when I lived on the ranch.
I also think a horse works better when he's not kept in a stall all the time. That's like keeping a kid in the house all day on a rainy day. When you go get him out he's feeling his oats and is ready to go burn some energy. Until you get him ridden down again he isn't going to work like you want him to. It's not fair to go jump on a horse Friday, ride him on the weekend, and then let him go all week again. Keep your horse ridden down so he's thinking about what he needs to do instead of being full of nervous energy.