Perhaps I'm biased because I play a less soft code of football, but you should expect aggression in a so called contact sport. When you are playing a sport as hard as you can big tackles happen, doesn't mean you are necessary being malicious. Soccer isn't really a sport that should generate much punch throwing, but when you are full of adrenaline and someone is getting in your face it happens. These offences are probably worthy of just a 10 minute ban IMO.
Now spitting and biting, while maybe not as dangerous as other stuff is just pure malevolence, you're not defending yourself, it's just sick and wrong and deserving of far more punishment than the other stuff.