How would you know it was merely out of revenge?
And how was Bhagat Singh related to Lala Lajpat Rai to seek revenge?
Lala Lajpat Rai was leading a non-violent movement, whereas Bhagat Singh's ideology was completely opposite. Had it been Mahatma Gandhi to die in that lathi charge, Bhagat Singh would still have done the same, because he believed in going for those who attacked the leaders. It is not called "revenge".
Bhagat Singh also used to write a lot. I have not read a single piece where he mentioned the word "revenge". And were it only for revenge, a personal vendetta, why would the Congress Party support him against the hanging, even further, why would Mahatma Gandhi, while deploring his act, want his sentence commuted to life?
You see, Hindu principles are coded in Bhagawad Gita that was sung right before and in favor of, a great and extremely violent war.
What do you think Krishn say to Arjun when Arjun implored why should he kill his kith and kins? If your answer is anything other than, "righteousness weighs heavier than blood", then I do not know what else to say.
Why do you think the day right after Chakravyuh, Krishn took Arjun to Jayadrath? Did Krishn give Karn any chance to defend himself? Arjun waited, but Krishn, the supposed author of Gita, was unrelenting. Was that merely for Arjun's revenge from Dyut Krida? No, righteousness demands sacrifices.
So, no - it was not for revenge. Bhagat Singh's act was to show that the imposed law of the Britishers will not be tolerated to such an extent that the ideals of the age are felled one after another with complete immunity.
And I thought you knew, that it was the criticism and appeal for his surrender from senior Congress leaders that he decided to let down his guard.
Read Bhagat Singh: Immortal revolutionary of India.
Bhagat Singh was in the same protest march with Lala Lajpat Rai when he died. Lala died on 17 Nov, saunders was killed on 17 Dec.
The Mahabharata war was a 'WAR', one in which everyone arrives in a battle field ready to do battle with proper shields and weapons. Even before the war starts, a warning is given by blowing the couch shells and then the war starts. That is ethics and morality even in war. The Hindu way of life.
Bhagat Sing was arrested in the Assembly immediately after he threw two bombs and fired two rounds from his automatic pistol which then jammed. Congress had nothing to do with it.
The only valid point you make is about Karna being shot by Arjuna. Morality is only between two moral person, not between and immoral and moral person.
There is nothing that indicates immoral action by saunders that warranted his death.
What you need to tell me is that there is no morality in war.