It all depends on the individual case. If a friend simply doesn’t want to discuss a certain subject he/she will easily brush off any argument by saying “well, I feel differently”. It is an obvious sign of someone not even caring where the dismissal of the argument leads: Tyranny; so what? or Peace; fine, so?
If you keep forcing the issue you will quickly turn into a bad parody of yourself.
Of course not, they are your friends.
Probably. If you suddenly find yourself in a discussion of anything related to politics, disclose your views and let them stand for themselves. If they are sensible they will persuade them, if not, you just need to prepare better next time. You must always remember you have the dissident’s views on the world. Every time you express your views you force people to consider at least two conflicting ideas, i.e. you bring about a state of cognitive dissonance. In this state people must either question their own beliefs, which takes a lot of effort, or simply just brush off your objections as “loony.”
Thus the moment all you can say is no more than “I am actually very surprised that you feel that way” is the very moment you have lost the argument. What you are doing, essentially, is making them look like the “dissident” when both of you are well aware that you are the “dissident”; You must always have an argument ready, facts that makes it impossible to just brush off your objections as the view of a dissident.
I have only had success with arguments of ethics a single time; my sister. The reason being she is a sociologist and she has the mental capacity to distinguish meta discussions from practical or policy discussions. Also, she can grasp how morality and conventions are distinct from laws in governing human behaviour. Lastly, we have all the time in the world to discuss such things and can take the time to read up on a specific issue.
More succes comes from consequentialist arguments, but they rarely work out in the long run. People can easily be in favour of government on one issue while generally disfavouring government on other issues or vice versa. Minarchists are a perfect case in point and, in opposition to some of the other replies you have received, I wouldn’t try to convince anyone to be a minarchist as a strategy towards convincing them about market anarchism. Leave that job to other minarchists and then, only later, piggyback on their efforts to turn them into anarchists. The other way you will have to pretend you yourself is a minarchists which is disingenuous, not to mention dishonest.