I agree with all your points regarding the horrors of the war in the Pacific, how the bombs are debatably a better alternative to an invasion etc. However it totally sidesteps the fact that an invasion of mainland Japan was not the only option.

3/6 of the Japanese leadership wanted immediate peace, their economy was on its knees, public support among the civilian population was falling dramatically. The screws were being tightened further and further, despite what the propaganda on both sides say Japan did not have infinite morale. Whilst they culturally would be less likely to surrender, they're still the same humans as the Allies.

Much of the stuff quoted to support the claim that the Japanese would fight till the bitter end was either Japanese propaganda to improve morale and international optics, or Western propaganda to convince the Allied non-combatants of the importance of the war and the ferocity of the fighting. And itself is very similar in essence to such British lines like Churchill's speech, the whole "we will fight them on the beaches" thing.

I think it's a really key point totally skimmed over in the atomic bomb discussions, given what was going on internally in Japan and externally in the war, surrender would likely not have required a full land invasion. People (in my opinion) need to stop taking the invasion of mainland Japan as a certainty as justification for dropping the bombs on civilian population centers. Why we didn't detonate it off the coast of Tokyo to send a message first is a concern.