No, it does not.
Snakes shed their skins as they grow. Snake skin doesn't 'stretch' or get replaced 'bit by bit' like ours does. They shed their whole outer skin when a new skin has formed underneath. The new skin is slightly larger than the old one - enabling the snake to 'grow' into it. The older a snake is - the less it needs to shed.
Not usually. Sometimes a snake will have trouble sheding its skin. This can be a problem. Soak your snake in a warm bath to help the skin shed more easily.
A snake sheds its skin, because it allows the snake to grow.
No, eels do not shed their skin like snakes. Eels have a slimy mucus layer on their skin that helps protect them from parasites and bacteria, but they do not shed their skin. Instead, their skin grows with their body and they may appear darker or lighter depending on their environment.
They shed it..
So that it can grow as it will have just grown out of it's old skin.
because there will grow big
It depends on how fast the snake grows. If a snake is growing quickly, it will shed more. If a snake is growing slowly, it won't shed as often.
If you're talking about just the shed skin from a snake - you can't do much with it, as it disintegrates over time. The complete skin (including the underlying tissue) can be turned into things like belts and shoes.
All in one go, like a snake - no. Flake by flake - sure.
Yes - if they have a injury to their skin - they will shed more frequently as their body tries to repair it.
All reptiles shed their skin. Reptile skin doesn't 'stretch' like ours does. Instead, when the current skin gets too tight, they grow another one underneath. They shed (or slough) the old skin, and the new skin allows them to grow a little more.