Updating your opinions as you gain more information and experience is always a good idea.
I will however disagree on your principle that humans are savage beasts. I will instead put forth the notion that humans must choose to be savages. Just as they can equally choose to be rational. Folks have debated nature vs nurture for years. I personally think nature gives a disposition and a starting point, one's environment greatly helps shape a person, and a good bit left over goes to free will. To claim people are nothing more than savages or even naturally tended towards being savages I think cops out of personal responsibility. A person can have a messed up set of genes or a messed up developmental environment, but they are still responsible and accountable for their own actions. Humans are first and foremost, thinking creatures. Barring actual mental disorders, they can opt out of morality, rationality or civility, but they do so of their own accord.
While I agree governments and police have a place in detering and punishing crime, this is entirely secondary to personal responsibility. A person's safety is primarily in their own hands. The police have no legal or moral responsibility to protect any specific person. Their responsibility is strictly limited to the "community" as a notion, or society in whole. It is a contradiction to say police are solely responsible for dealing with crime but they have no responsibility for protecting any specific person. They physically cannot protect every person at all times, even if they or anyone else wanted to. This reality is what it is and can't be changed. In light of this, it is insanity to claim that the government has a monopoly on dealing with crime. Any person that is rational must make their own preperations as they can.
The question of why do people need freedom is simple. They don't need it, because they are born with it and these freedoms become void only in death. All government is based on the consent of the governed. The proper question is how much freedom should be delegated to government to fulfill the roles we see fit to have them perform. The answer we have is the Constitution. Even a cursory reading of the Constitution explains that only specific tasks are within the government's realm. Everything else is retained by the states, or by the people themselves.
You could be perfectly capable of believing that that gravity does not exist. That is your right to believe the irrational. It is equally rational to deny gravity as to believe that rights or natural laws do not exist. You may wish that these do not exist, but like gravity, they exist regardless of one's wishes.
People do not need freedom in order to change a government. They must merely withdraw their consent. Through the ballot box, popular dissent, or the barrel of the rifle. Most often governments are changed because the previous government had usurped enough freedoms that it would not be tolerated.
I do believe you may be operating under the believe that someone hands out rights. Whether by some deity, some government, whomever. Rights are not handed out at all. They are created out of the consciousness and rationality of the human mind. They can not be destroyed, only transferred by consent or inaction.
