Nice start but it is missing some of the details that make the process easier and more efficient.
For example she talks about tearing the skin but doesn't mention the primary reason why. If you are tearing the skin odds are your scald
water was to hot. That number I don't remember but there is a peak temperature to scald at that is fairly critical. The other common reason for fragile skin is to long a scald. That one
should be 35 to 45 seconds moving the bird with a pumping motion in the water to work the water into the feathers to get an even scald.(if your water is getting borderline to cold the length of scald has to go up) At any rate mom always measured the water temperature and we always took it right to the maximum temperature so we had the most room for error.(like an interruption of some sort) If the water is to hot add a bit of cold and stir till you get it down to max. If we were doing lots of birds the water temperature was measured every 4 or 5 birds to be sure it wasn't getting to cold too. About 5 birds per person to dress out per day is about all most people can stand to do in a single sitting. Beginners should start with just one or 2.
Feathers that are hard to get out mostly are caused by to low a scald temperature, uneven scald or scald not long
enough. If scalding water fowl because their feather repel the water the carcass should be wrapped in a terry cloth towel immediately following the scald to let the steam work on the scald after it stops. Feathers in younger birds or close after a molt are typically harder to get out too. Now one grandmother insisted that there should be some baking soda in the scald water because it made feathers come out easier. I couldn't tell any difference but it was part of the family lore. My mother never worried about it. Don't know the truth on that one but it might help someone.
She didn't mention the grip for plucking feathers. The index finger is folded tightly back to the hand and you are pinching the feathers between it and the side of your thumb.(rest of the fingers make a loose fist) Getting started in the season your hand may cramp while you get used to the finger position. The advantage of this over just pinching with fingers is higher grip strength and a broader pincer to take more feathers at once, making you faster.
She also didn't mention the direction you pull matters. It should be at a slight diagonal against the grain of the feathers in most cases.(there are exceptions) Makes the pull easier but more importantly tends to trap a few more of the pin feathers so you get a cleaner skin easier. Young birds are the primary source of pin feathers but wrong season butchering laying hens can be a real problem too. You want to avoid dressing
chickens in the month or so following the primary molt for the year as the new pin feathers are still coming in. Against this typically if you are using feathers and not down to make a bed the feathers loft is better early after the molt. So you can have competing interests. Another part of this is how you tension the skin with the other hand which she wasn't doing much of. This can help make you faster as well. We always sat down to dress birds and did them on our laps. Less fatigue so you can do more birds. It is a bit messier. Usually a sack cloth type dish towel was spread on the lap to keep the worst of the mess off clothes. Her way is way most definitely neater to your clothing. We always plucked either around the burn barrel or around the
compost pile if we were not gathering the feathers.
The reason that you want the skin is because it contains and has just under it the fat that gives you the best flavor and you need that fat if you are going to make the best tasting gravy or best tasting broth.
If you are going to skin some and pluck some the pin feather show less on light colored birds so if you have a choice ideally you skin dark birds and pluck light birds. Remember pelts from some mature skinned
chickens can be valuable to fly tiers. Some varieties with really good quality feathers are worth far more than the chicken. Be sure you treat against insect damage here. Untreated can be ruined by bugs in less than a year. On the other hand I have 30 and 40 year old hides that were treated that we are still tying flies with.
Pressure cooking reduces cooking time to get a tender bird when cooking older birds should be mentioned for beginners too. Canning the chicken meat because of its combined long cook times also helps deal with older tough/chewy meat. You get more flavor when canning if you are making stock that includes bones while cooking. Now a grandmother doing stock that she wanted to be her best stripped all the meat off the bones and then put them in the
oven and cooked the bones till they started brown on the outside. They went back into the stock to cook down some more. Done correctly this was supposed to improve the flavor. Go a tiny bit to long though and it makes things taste burnt instead. This part is an
art as much as a science.
Now one other thing that my mother always did that I find horrifies other people but I feel is part of the respect for life. Every year there were a few real friends in the chickens who got names. When butchered and packaged individually mom always wrote the name of the bird on the package. Then while eating that bird we usually had what amounted to a mini wake in honor of that bird while we ate it.