Ethical questions like this are a lot easier to discuss if you take for granted that people are acting in good faith.

If you truly cared that much about Amazon and truly felt library participation was so heinous that it ought be obstructed, I think a lot of people would be very skeptical and a lot of people would disagree with that perspective, but yes, those of us who believed you were acting earnestly would indeed appreciate you standing up for your principles in a way that was impactful but not violent.

There's less skepticism of sincerity here and more agreement with the fundamental concern here, but the respect for principle and action covers both, yes.

It's civil disobedience, at least once she refused to step aside when told to do so by the police officer. (I don't know if she was breaking the law by obstructing the robot.) So yeah, I would say there is nothing inherently wrong with you obstructing the entry of the local library -- provided you are willing to be peacefully arrested.

That doesn't mean that I agree with your right to obstruct entry into the library, nor does it mean that I agree with your reasons for blocking entry to the library. I also suspect that the courts would reject your reasoning.

well yes. if you are OK with getting arrested and charged for demonstrating your political convictions, I support your nonviolent protest. this isn't the gotcha you seem to think it is.

That is how picket lines work, yes.

As long as you agree with the consequences of that (You'll be arrested quickly), sure why not?