No, the government may not properly outlaw any of the practices you describe, as long as they involve only consenting adults. IMO, animal cruelty is a legitimate area for government regulation, since obviously the animals can't consent. Some forms of bestiality would fall under the cruelty umbrella, but if someone enjoys encouraging their horny canine to hump them in their own home, I hardly see any benefit to government agents undertaking a prosecution. As far as I know, there's not a single state which outlaws humane killing of animals in one's own home, whether for food, or euthanasia of sick/unwanted pets or farm animals, or pest control -- nor should their be.
Luckily, almost no one on earth agrees with you.
Your position isn't conservative--as you claim--it's ultra-libertarian. That's fine. Admit what you are. Embrace it. But you aren't a conservative, and you can't admonish conservatives for not being libertarians.
Untouched are my questions about the regulation of family practices. Does government have the right to require Christian Scientists to get medical attention for their children? What about corporal punishment? Obviously there is a point where this becomes harm. It isn't obvious to me that this point of law should be left up to individuals alone. Your argument has a problem, because in many cases it's up to the polity to decide when in fact any actual harm has occurred.
Untouched also the question of abortion. Regulation of personal reproductive procedure, or is there a human harmed in the process? Government needs to make that call, one way or the other, as a matter of life or death.
All pure libertarian arguments ultimately fail because the answer to the question of actual harm is seldom clear cut, and must be decided--by government--in advance. That is why government of, by, and for the people matters.