I don't know if someone has already replied this because I have not read all 4 pages of posts.
I sell the older hens on Craiglist of Facbook marketplace and I always have buyers. I only keep hens up to about 4-6 years old before I sell, with the exception of a flock mother - a hen with particularly watchful eye, good leader for the flock, even tempered, and a good egg layer that also goes broody at least every other year. Sometimes I'll have two older hens if leadership of the flock is balanced like that.
As far as meat goes, I also raise chickens for eggs and meat but I only cull the roosters. I have never eaten a hen. The reason is because I let the hens grow up from chicks to about 4-6 years before I sell them and by that time they are not good for meat. At least that is my experience - older chickens, whether male or female, have tough meat.
So the best breeding plan that I have come up with, to get both eggs and meat and keep the hens young, is to start with an all-purpose chicken breed - one good for meat and eggs and with natural instincts to forage for food and with a high likelihood of going broody.
At the start of the year I'll have one rooster - the biggest and best of the flock. He fertilizes the hen eggs during the spring and once new chicks hatch, he too gets culled for meat (usually).
In my flock at least two hens go broody every year, so they sit on fertilized eggs in the spring. Often times there are three hens broody in the springtime and sometimes there are four. What chicks they hatch out will be, obviously, about 50% male and 50% female. There is no sexing chicks when nature does its work. You get both male and female equally, but it works out very well if you want both meat and eggs.
Chicks hatched in the late spring/early-summer grow up through the summer and fall. By Oct, when the males are starting to show signs of aggression and sparring, it is time to start thinning them out (culling). A flock my size only needs one rooster once they hit full maturity. Any more and the hens will suffer, as well as the weaker roosters. So the plan I use is to go about culling roosters for meat through intentional selection.
At this point you can chose what traits you want to carry on through your flock because you are going to leave one rooster alive at the end of it and he will fertilize the next year's eggs. I cull the weak and small ones first, before they get too beat up by the larger ones. I then select for good leadership traits and a fair temperament. I make my selection for "breeder" by the end of the calendar year and I cull the rest. One year I actually had two really good roosters and I could not decide which to keep so I divided the flock and kept both, and breeded both.
Every year I not only get several males for meat, but I get several females to keep the flock young and the egg production high. That means that every year I have to part with the older hens, as mentioned, by selling them online. If I wait until the hens are 7-10 years old not as many people want to buy them. Older hens do not lay as many eggs and I always post the age of the hens that I want to sell.
So by January I have one strong rooster left and the process repeats itself for the rest of the year. That last rooster gets culled once a new brood has hatched. There has only been one exception to that rule - Boromir, son of Aragorn - the best darn rooster I have ever had. He lived 3 years but died by some still unidentified predator.
So you asked also about being more "thick skinned" and not looking at chickens as "quasi-pets". To this I will only be able to relate how I am able to name all of my birds and still carry out the culling needed. I do see my chickens as 'pets', or quasi-pets. Obviously I am closer to my hens than I am my roosters, as the later have a short life spanned. As mentioned, I have only really ever 'liked' one rooster. Roosters are actually easy to dislike. They make it easy with how they treat each other, how they treat the hens and sometimes how they treat you.
The main thing about raising chickens, when culling for meat is involved, is that you have to primarily see yourself as a caretaker of the flock as a whole - not the caretaker of an individual bird. When you think like a caretaker of a flock - the flock being the organism - you make decisions regarding overall flock health. So when you hatch out, let's say 30 eggs to chicks, you'll know that is no way that 15 roosters will be healthy for your flock. (You can consider that about half the chicks will be male and half female.)
Now YOU have to manage that. Taking care of the whole flock is our responsibility, even to the demise of an individual, for the sake of the whole.
I hope this helps. Sorry so long.