If you substitute the word "immediate" for "real," we are in agreement.
That fact that the immediate cause was the seizure of American ("Federal") property and subsequent secession of the Cotton States, along with Lincoln's conciliatory attempts to save the Union as his principle short-term goal, has caused no end of mischief with Lost Causers, who want to pretend that what was merely the latest case was the actual cause of the War.
Unfortunately for them, one has to ignore the foundational basis of the Republican Party, Lincoln's own personal history, and nearly the entire history of intra-American disputes from the 3/5 Compromise going forward to believe that slavery was not the real cause of the War. (Actually, you can go back further than the Constitution, and even before the Revolution.)
The question of Southern Honor puts me in the mind of Emerson's famous phrase: "The louder he spoke of his honor, the faster we counted our spoons..." but yes, I will concede there was a large element of that. But actually, I believe there are two other important causes that you miss: 1) The slavers (as distinct from Southerners, generally) had bargained in bad faith for years. The election of 1860 precipitated a crisis because it was now clear that the three separate parties all calling themselves "Democrats" could no longer keep a coalition together well enough to retain Federal power. 2) New York and Pennsylvania had both eclipsed Virginia as the most important states of the Union. They were both far more populous by 1830, and in the succeeding 30 years industry had lifted their ascendant populations out of poor immigrant status. The prestige and influence of the South was rapidly waning. This produced in the slavers a "crisis mentality." (Which the election drove forcefully home.)
As to rest, we agree. The Charles and Mary Beard version of history and its many variants are pathetically silly, and the fact that it was taken up by academia so enthusiastically (and its various incarnations have managed to survive despite Beard's own demise) is a testimonial to the fact that "progressive" academia is nothing very new.
Or as my Dad once put it, in reference to the wars in Iraq and Afghanistan and the "no blood for oil" idiots: "I didn't sign-up for the combat infantry on December 10th, 1941 because of the expansion of US markets into the Far East. That's all crap. I signed up because of 2400 dead guys at the bottom of Pearl Harbor, and so did everybody else."
Duty, Honor, Country, yes.
Money? No.
I prefer your wording.
Although you can make a decent case that an anti-slavery majority in Congress could immediately start whittling away at the viability of slavery using perfectly constitutional means.
For instance, interstate commerce in slaves, even between slave states, could have been prohibited under the appropriate clause.
I'm not enough of an economist to know how this would have affected things, but certainly the Upper South and Border states, with export of slaves to the Deep South a critical components of their economy, would have been severely affected, as would the Deep South states, which needed those slaves to keep expanding their acreage under cotton.
In fact, I would suspect that just the threat of such a closure would make the South suddenly a lot more reasonable about considering gradual emancipation in return for not immediately implementing the proposal. Except of course that they would have not considered any such thing, they would have seceded. But in this scenario with a little more justification, to the extent any action in defense of slavery can ever be justified.
What "dead guys" did Lincoln invade the South for?