There are two kinds of DE. One is processed for use in swimming pool filters and the other is processed for insect control. The latter acts like tiny pieces of glass and grinds up or cuts up the insects exoskeleton. It becomes harmless when is gets wet so I don't understand why one would not...
I would never ever feed my hens egg shells no matter how finely the shells are ground up. I did that once and had nothing but problems with the hens pecking their eggs. I had to get rid of the whole bunch and start over.
You bet you can feed them pumpkins. I sell them at my business and feed the leftover ones to the flock as a treat. I break them up with a shovel and let the hens at it. If your pumpkin is soft to where it's moldy toss it. Don't feed it to them unless you would eat it.
I have 6 RIR hens about 3 mos old. Someone gave me a young roo about 5-6 mos old. He was red with green tail feathers. Within a couple days he bit a hole in the back of the neck one of the hens. Of course the other hens joined in the pecking. I isolated the injured bird, got it healed up and...