I've been battling mites for a while now. I'm pretty sure they're Northern Fowl mites since they stay on my poor kiddos during the day. They will move from the chickens to me when my sweeties sit on my shoulders and lap. I'm treating their house with permethrin (spray and powder) and them...
I understand the pecking order and can see how it works with just the girls. When the RIR would see the sexlink out free-ranging, he'd charge at her and chase her right into the chicken coop. He would not even let her come out of the house. The Serama was the same way. I do have some bossy...
I've had chickens for about ten years, but I'm not very experienced in terms of roosters. I've only had a few, and I owned them for several months or less before finding them a new home (not for soup). My most recent two, a Serama and a heritage Rhode Island Red, hated my elderly Gold Sexlink...
Chickens are fabulous therapists. If I'm sad or upset, I visit with the girls for a while. The friendliest ones sit on my lap and shoulders. They fix my hair for me, or just talk sweetly. I wouldn't give that up for anything.
Chickielady has Jersey Giants. Rainwolf has Ameraucanas. If you'd like, I can ask Rainwolf what she has available (she hasn't been on BYC for a while).
I'd try putting him on CL. While it's true that people get CL roosters for dinner, they're a lot less likely to eat them if they have to pay for them. Since SFHs are pretty uncommon, there's a good chance that you'll find someone who is genuinely interested in him because of his breed. Good luck!
Of course, you'll want to make sure predators can't dig under your fencing. I'm sorry if I'm giving advice you've already followed, but it's important to cover all bases.