Edward --

Taking your items on list individually, aside from slavery, here they are --

1) taxes,
2) free trade,
3) import and export issues,
4) California,
5) bleeding Kansas,
6) westward expansion,
7) Constitutional protections, the Bill of Rights.

1) Since there were no direct Federal taxes in antebellum times, the tarrif on imports and exports represent the only tax issue. Unless a citizen was involved in overseas trade, this issue did not affect people. Little was written about it during the 1850s.
2) Free trade became an issue after the Civil War because Republican leaders opposed it. Replublican were not in position to enact Federal policy until President Lincoln took the oath of office, with strong Republican majorities to back him. For example, "In 1895, Theodore Roosevelt said, 'Thank God I am not a free-trader. In this country pernicious indulgence in the doctrine of free trade seems inevitably to produce fatty degeneration of the moral fiber.'"
http://online.wsj.com/article/SB10001424052748704696304575538573595009754.html
3) Same as 1).
4) California. California? Abraham Lincoln used California and the recent discovery of gold there as an object lesson to non-whites as to why white people were successful. He explained how gold had remained undiscovered by "Indians and Mexican greasers" for centuries until the Yankee set foot on the land.

To be fruitful in invention, it is indispensable to have a habit of observation and reflection; .... But for the difference in habit of observation, why did yankees, almost instantly, discover gold in California, which had been trodden upon, and over-looked by indians and Mexican greasers, for centuries?

http://showcase.netins.net/web/creative/lincoln/speeches/discoveries.htm
But Edward, what was so controversial about California? Did the government intend to give it back to Mexico?

5) Bleeding Kansas was simply a rehersal for the Civil War in a struggle for control of the state government between abolitionists and slaveholders. Not all Southerners who came to the Kansas Territory owned slaves, such as the man I quoted a few weeks ago. But like him, they came with the intention of bringing Kansas into the Union as a slave state. That's what created the conflict.
6) Westward expansion. Southerners moving west into the territories found themselves in conflict with those who not only wanted to exclude slavery; they were dead set against having anyone other than whites as settlers. Note the last sentence in this antebellum speech by Abraham Lincoln.

they tell us that the negro is property anywhere in the light that horses are property, and if the constitution gives the master a right of property in negroes above the jurisdiction of the territorial laws, enacted in the sovereignty of the people---it only requires another case and another favorable decision from the same court to make the rights of property alike in states as well as territories, and that by virtue of the constitution and in disregard of local laws to the contrary---Buchanan takes this position now. Sustain these men and negro equality will be abundant, as every white laborer will have occasion to regret when he is elbowed from his plow or his anvil by slave niggers.

Speech in Carlinville IL, Aug. 31, 1858.
http://quod.lib.umich.edu/cgi/t/text/text-idx?c=lincoln;cc=lincoln;view=text;idno=lincoln3;rgn=div1;node=lincoln3%3A7
7) Constitutional protections, the Bill of Rights. The only direct application to the 1850s would be Southern concern about equal protection under the law. During those years people living in the Southern states came to believe that the Federal government was not protecting them or defending their constitutional rights the same as those of other citizens. This became a major factor in the Southern Rights movement.

It would seem that most of the topics listed above are meant to refer to Southern Rights, a movement which eventually led to seession.