It is likely impossible to tell what type of snake it was by the shed skin. If the head was largely intact you could look for indentations on the side of the face that might be the heat sensing pits of pit vipers (rattlers, cottonmouths, etc). But this would be highly highly unlikely:)
being 3 feet in length could be many many types of snakes. For sheer probability, it depends on where you live. By numbers, some species of water snake (nerodia), rat snake, etc would be probable.
Sheds are not good identifying factors, unfortunately.
No, sexing a snake should be done properly by poping or probing by a professional.
You can't ! Males and females have the same colouration !
Yes you can, the skin is pigmented; it's like a translucent version of the snake.
You can usually tell when a snake is going to shed when there is a dull looking film over the eyes of the snake. Most of the time a snake will not eat when it is getting ready to shed it's skin, and there may be flaky, dry skin on it's back. Once it sheds, it's scales will have a different appearance. The snake will have a smoother appearance, and the eyes will be very clear and lose the dull appearance.
no discharge from any parts of the body, clean sheds, eating normally, no signs of pain or discomfort
looking at it
no, you cannot accurately tell if a snake is venomous by its skin. the only way to accurately know if a snake if venomous is to look up the snakes native to your area and learn to recognize them. this way you can easily avoid the dangerous ones.
yes they do. they can eat you alive so watch out. if you see a snake of any kind tell a snake expert to come get it .do not run from it.
The old skin gets too small for the snake, so he sheds it and a new one grows in it's place. You can tell a snake is about to shed by his eyes; if they are cloudy, the old skin needs to go bye-bye.
a baby rattlesnake has "a bud" at the end of it's tail. The bull snake has a tapered tail with the same type of skin.
It sounds like a king snake, they are harmless. I cant tell you what kind it is because it depends on were you live.
you ask an expert and don't trust random people online.
Rat snakes are generally black whereas corn snakes are orangey yellowy and look like ground up corn.
You can get an approximate age by counting the number of segments on the rattle. This is only a guide, however - as the snake adds a new segment each time it sheds its skin. Young snakes shed much more rapidly than older ones - sometimes three or four times in a year.
Nope - unless the skin has feint pattern markings on it - then it may be possible to identify the species.