Well I'm new to this too so i can't answer the blood feather question but the quick is the vein in the nail just like in dogs and cats. The part that is red if nails are clear but you cant see if nails are black. If you cut too short you'll nik the quick and the nail will bleed.
I was looking for the same info. I can tell you that I use vinagar and water to rinse my chickens when I wash them so I know that won't hurt them. I haven't heard of using baking soda so not sure about that.