We must tailor our response to the people we are dealing with.
Rainbow signs in a shop are a symbol of open warfare against God, and it cannot be the correct response to just go to another shop and ignore it, as that amounts to letting the evil accrue. LGBT activists are in open warfare against God; they must be fought. With a person who is struggling privately with sin, a soft approach is good; but with those who are waging war and going about to spread the evil, that calls for a harsh response.
About the man with the rosary - were the people he was engaging with LGBT activists? I couldn't determine. If they were activists or paraders (paraders should be seen as activists), then his response to them was appropriate.
The only violence we are called to as Christians is violent destruction of our own sin by the power of God.
Calling for violence against other human beings in the world is anti-Christian and shows a lack of knowledge, or lack of care about what Christ taught.
"Therefore you have no excuse, O man, every one of you who judges. For in passing judgment on another you condemn yourself, because you, the judge, practice the very same things." Romans 2:1. I have never personally been to Sodom but I spent a lot of time in the "surrounding cities" of fornication and lust and regrettably still do, mentally, at times. Not just Sodom, but the surrounding cities also, were destroyed by fire. So when you wish for God's judgment to fall on sinners, and even hasten to bring it about by yourself in your ignorance, you may be calling down fire on your own head as well, since Christ commanded us to love our enemies and wait for the day of His wrathful judgment, not try to execute our own.
"Know this, my beloved brothers: let every person be quick to hear, slow to speak, slow to anger; for the anger of man does not produce the righteousness of God." James 1:19-20
"Then they came up and laid hands on Jesus and seized him. And behold, one of those who were with Jesus stretched out his hand and drew his sword and struck the servant of the high priest and cut off his ear. Then Jesus said to him, 'Put your sword back into its place. For all who take the sword will perish by the sword. Do you think that I cannot appeal to my Father, and he will at once send me more than twelve legions of angels? But how then should the Scriptures be fulfilled, that it must be so?'” Matthew 26:50b-54
"And when those who were around him saw what would follow, they said, 'Lord, shall we strike with the sword?' And one of them struck the servant of the high priest and cut off his right ear. But Jesus said, 'No more of this!' And he touched his ear and healed him." Luke 22:49-51
I am not saying we should condone perversion or any other crime against God, but the place to begin fighting those is within ourselves. Unless the man with the rosary is without sin and thereby worthy to cast the first stone, he would be better off to follow the command of God: "Be angry, and do not sin; ponder in your own hearts on your beds, and be silent." Psalm 4:4
The kingdom of God is not of this world, and we are mistaken in trying to execute our own judgment and punishment, especially since we understand so little of what is actually going on.
Jesus answered, “My kingdom is not of this world. If my kingdom were of this world, my servants would have been fighting, that I might not be delivered over to the Jews. But my kingdom is not from the world.” John 18:36
"For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places." Ephesians 6:12