Cats behavior is an enigma to the people who spend their time these animals and care for them. A cats behavior is not the same as human behavior and cat control can not be achieved by using methods that are based on faulty assumptions.
Humans are not pure carnivores or predators but cats are. They play and eat and have the way they do as part of their history of living as hunting creatures in the wild. Too many humans try seeing cats behavior in human terms and understanding and this causes conflict. We would never expect an elephant to act the same way that a parakeet does, but many cat owners expect their pets to act human.
When dealing with discipline issues with your feline friend, physical discipline typically does not work and can cause your cat to react in an aggressive and hostile manner. Alternately, using a sharp "No" and then removing the cat from the area consistently will be more effective. Most animals will respond better when they are awarded for positive behavior and admonished for bad behavior.
Sometimes cats act a little crazy, but a lot of these behaviors come from their instincts. When they spray urine, they are marking their territory and protecting their breeding group. Of course, people do not appreciate such behaviors. Training can work, but if you are not planning on breeding your cat the best choice is neutering.
If you are concerned about your cat scratching furniture or your pants, there are several products available for your feline friend. Cats work hard to keep their claws trim and sharp and need to be trained to only use scratching boxes or posts. Your veterinarian can assist you in selecting the best scratching products and toys to aid in protecting your furniture and clothing.
Safe, durable cat toys will help your cat feed his need to stalk prey and play with it by chewing and worrying it after the capture. Any cat which goes outdoors regularly will always bring you a "gift" by proudly presenting you with a small animal he has just killed. Never punish or scold him for this behavior. Although it may be totally disgusting to you, it's just doing what comes naturally. Keep in mind that you do not need to praise him for it, either. You'll find that even an indoor kitty may sometimes bring you a mouse or insect they have stalked and captured in the house. He's just showing you his respect.
Consider that your cat's behavior is not a bad behavior, just something that is coming as part of their natural makeup. Your cat was designed to live independently outside and may still have a reserve of a wild lion side. Their basic instincts will show through from time to time and it is better to try to understand the reason a cat does some of the things it does than just assume it is a bad behavior.