As an American, I had always heard that the primary reason for dropping the atomic bombs on Japan was the idea that it would be a bloodbath invading the country with no idea of when they'd surrender. But in a recent visit to the Hiroshima Peace Memorial, the only two reasons they had listed were justifying the cost of the Manhatten project and ending the war quicker to prevent the spread of Russian influence, with no mention of the what I had learned.
Is there a general consensus on the primary reason for the bomb drops, or like many things in history, is it a hodgepodge of reasons with each country leaning towards the reasons that are more favorable to their argument?
Much more could be written, but you might like to see the FAQ section "The atomic bombs, aka questions /u/restricteddata has answered" . Aside from the eponymous user, /u/t-o-k-u-m-e-i and /u/ScipioAsina are also mentioned.
One reply in particular, "Did the US have to nuke Japan in WWII?", touches on some factors that you mentioned.
In this AskHistorians reply , restricteddata pointed to an outside article, "Were there alternatives to the atomic bombings?", which was written by restricteddata (published under his real name).
This is a starting point, not to discourage discussion. Especially because previous dicussions here tend to look at effects after the fact, especially discussing what factors had caused Japan to surrender, rather than the reasons before the fact.