At two years old he is unlikely to change. That behavior is fairly typical of an adolescent but he is well past that stage.
More hens or less hens won’t make any real difference. You can have the same kinds of problems whether you have one rooster with one hen or one rooster with 40 hens. Some people love to have magic numbers where they can put something in a box and have it happen the same way every time, but you are dealing with living animals. Real life doesn’t work that way.
Some hens have brittle feathers. No matter how gentle the rooster is the feathers just break really easily. That’s not the rooster’s fault, it’s genetic. I’ve solved the bareback hen problem in my flock by removing the bare backed hen, not the rooster. Since those genetics were not passed on, I no longer have a barebacked hen problem in my flock. That option is not available to everyone and brittle feathers is not always the problem either.
Have you checked them very carefully for mites or lice? Roost mites only come out at night so you really need to check after dark when they are on the roost. Sometimes mites or lice can cause feather loss.
The saddles will not interfere with dust bathing or anything else. You might want to make sure they are made out of wool because that handles being wet better than most other options. To me the only concern with saddles would be wet cold weather.
The hens have a part to play in mating too. Most people ignore that part of it. They have to accept his dominance, that’s just the way flock dynamics are set up for a peaceful flock. Some hens can’t do that and some roosters cannot win the hen’s confidence. Each chicken has its own personality. They are living animals.
From what you are describing he is probably a jerk. Some of your hens being bare backed is not what makes me feel that way, that could be due to something else and not anything the rooster is doing. It’s that one hen’s reaction to him. Even that is not clear cut. Sometimes there is something wrong with a hen and the rooster won’t accept her in his flock but will be pretty brutal to her, trying to run her off or even kill her. The hens will sometimes do that too.
It’s really difficult to know what is going on for sure with your flock, especially from across the internet. Sometimes it is difficult when looking at them.
Yes, it can be very difficult to find a good forever home for a rooster, especially if he is a jerk. When someone else owns him they own him, you don’t any more. What they do with him is up to them.
