>>4151071) boiling removes the grease they use on new traps to prevent rust and also odors if you are trapping canines. Dying protects them from rust.
2)22 on the head center of skull right above eyes
3) you can sell them green which is just the hide removed the animals. The other and most common option is to flesh them then sell them. If you wanna see how to flesh coons check out coon creek outdoors on YouTube professional fur handling vids.