Sasheena - I'm not Glen, but I'll give you my opinions/answers to your questions.
Most of the hatchlings from a clutch will shed generally within days of each other. I usually wait until all have shed, then feed. Having quite a few clutches hatching and sheding at different times, I would probably go nuts feeding everyone as they shed. I feed everyone all at once, and if some hatchlings haven't shed yet by feeding day, I feed anyway and better than half of the "non-sheds" will eat anyway. I don't feed "just hatched", because that is really too early, but by the following week, they'll get fed.
Most of the time, I feed everyone once a week. Small hatchlings will often be fed a little more frequently (every 4-5 days), but not all the time. I tried feeding all my hatchlings every 4 days one year, but got many more refusals on an almost regular basis. Going every 5-7 days seemed better...the hatchlings had time to fully digest their meals and were quite ready for the next.
For the first 2-3 months, I don't like to go more than 7 days between meals unless I absolutely have to, and never more than 10 days. I want the hatchlings to have the best start possible and gain as much strength as possible before they get exposed to any stress (travel/sale/missed meals/extra handling, etc).
I have about 250 breeder mice and start saving pinkies when my adults come out of brumation. I usually have enough to feed the 100 plus hatchlings until I sell them in August, but start running low at about the same time. There have been several years when the mice just didn't produce like expected and I had to buy pinkies. And now that I'm expecting even more hatchlings, I have to expand my mice colony. I also breed rats to feed the older snakes (pinkies can't grow up to feed yearlings and beyond if they're fed to hatchlings), but even the smallest rat pup is way too big to feed the largest hatchling corn. Small rat pups are about the same size as fuzzies or even jumper mice, at least in my colonies. Perfect for the average yearling, and rat pups grow rapidly to the small, med and adult mouse size, which my older corns love.