Uh, no. I don't pretend to know the abolitionist history of the North outside New England, but I certainly know it here. Abolitionism in the North, even in New England, was seen as a radical force not to be engaged with, save for the Quakers. It was the South, for political reasons, that engaged the subject as if nearly every last northern white was providing shelter for the Underground Railroad. Most in the North simply couldn't be bothered by the subject in the timeframe which we all seem to be addressing (1830's,1840's). New England itself did not finally abolish slavery until the start of the 1840's.
Umm No, New England was done by the '20s. New York freed all of its slaves in 1817. the Northwest Ordinance of 1787, guaranteed no slavery in the new Ohio and Michigan territories. The North didn't want to touch the issue because it was the 3rd rail of American Politics. Much like Entitlement reform today, except no one talks about it. There was an actual gag rule on slavery until I believe the 1850s. Slavery was the unspeakable issue. The Founding Fathers had deemed it so by failing to address the issue, and the South was more than happy to expand it while the North was more than happy to not engage it. There were more people for Abolition than you think, The radicals were just vocal about it is all. JQA for one, Zachary Taylor, Daniel Webster, Millard Fillmore. To name some prominent people. People just didn't talk about it. You are correct in pointing out, that it was a radical set for sure, but all it takes is one radical or one percieved radical to light the keg and then you get tea party protests.
If the Yankees are only just getting around to freeing their OWN slaves, how much enthusiasm can you expect of them to demand total national abolition, even if it means civil war?
Who said they were going to demand it? Maybe all the North wants to do is discuss the issue? I think that coupled with the "tarriff of abominations" will be enough to tip the South. Remember we are talking about Elites not the rank and file. Alot of people will be up in arms simply because there boss is.
It was simple brinkmanship on the part of southern politicians to threaten civil war whenever they didn't get everything they wanted on every possible issue. My God, South Carolina took up a secessionist movement (and a very hysterical one I might add) in 1837 over tariff rights!! The southerners before the civil war had civil war on the brain. The north simply was too willing to accommodate the south's wishes.
To address your main point, nothing the South did in this period makes sense to our modern eyes, that doesn't mean it didn't make sense to them. On the issue of Tarriffs, these are huge issues because this basically the only tax that people paid at the time (liquor taxes was another) so it seems reasonable that people would get up in arms over Tarrif hikes during that time. All it takes is a president who doesn't want to compromise on slavery or Tarriffs and who doesn't scare the hell out of the South. The secession movement of 1832 had similar motives to 1837 (this is one I am less familiar with), in 1832, Jackson did two things that diffused the situation, 1, he changed the officers and customs officials in Charleston, 2, he agreed to reduce the tarriffs. This was a in 1832 movement was serious enough to warrant Jackson taking a 2nd look at policy and Jackson was someone who didn't back up for anyone. You are right the South had seccession on the brain and this why a politician less skilled than Jackson would almost certainly screw the pooch.
The compromises made in 1820 and 1854 (before and after the period in question) saw to that. Almost every president from after the War of 1812 to Buchanan was either a southerner or southern sympathizer. The north was too ready to deal, the south would not secede just for the sake of seceding.
Another quibble, the compromise of 1850 (1854 is the Kansas-Nebraska act also a compromise) came about because Taylor refused to allow slavery in the new California territory. This was deemed treasonous by the South who thought Taylor one of their own (he was from Louisiana).
So much of this legacy is built around Jackson it is impossible to tell, if a compromise would even come up. Jackson was the overarching figure of this period of time. I think an Age of Jackson without Jackson will see much more polarized politics to the left and right (then they already were) , not to mention the nation was a powder keg waiting to explode and Jackson was the only man who could manage the situation because he was just as explosive as the times and was willing to threaten the steps necessary to get the South to toe the line. Any potential president in this period from '28-'60 does not have Jackson's force of personality any potential situation that would come up would not have a framework within which to work.