Lincoln, like most people of the time, was opposed to race-mixing. There is nothing new here, either.
The key point of difference is that Lincoln and the abolitionists believed in the fundamental humanity of the black man and the founding principles of the nation. Many southerners of the slave-power conspiracy believed in the racist ideas that Negroes were sub-human and biblically condemned to slavery. By the 1860's the south had denied the vision of Jefferson and Madison, in favor of the heresy of Calhoun. If you don't believe me, read CSA Vice President Stephens' "Cornerstone Speech" sometime. Speech"
There's no need to qualify or nuance his support for colonization AND immigration, capitan. He favored it both to Africa and other colony locations, period. He died a proponent of it, period.
Lincoln's words were that he believed that while the black woman should be allowed to keep the fruit of her labour, that did not mean he wanted to marry her.
Lincoln understood that civil equality would take longer then human equality, as set forth in the Declaration of Independence.
I agree with you that before his death, Lincoln moderated his view of black capabilities because of his contact with men like Frederick Douglass. Field hands wouldn't impress, but Douglass showed him what education could do in a black man.
The political problem, however, would remain, and I'm sure he saw that, too.
One of the bitter fruits of slavery was that it annihilated tribal, customary, and linguistic particularisms among the imported slaves, and Americanized them very rapidly, so that black Americans have reasonably been described as the most American of Americans, since so very little remains of their African cultural heritage -- although more and more of it is being gradually recognized by scholarship: "shotgun houses", I've recently been told by an archaeologist interested in slavery and antebellum historical archaeology, were actually an African floor plan replicated over here by emancipated slaves. The word "shotgun" itself is said to be a corruption of an African word that describes the floor plan, rather than the folk explanation we usually hear.
Nevertheless, blacks were almost universally seen as being outside American society, both North and South -- hence the colonization idea -- and Lincoln will have recognized that assimilation of the black population would always be controlled by the biological fact of partial dominance and the American distinction of all "colored" from white society. We never had "statutory white" people in the United States, just a few examples of people who "passed", with the connotation on both sides of the color line of fraudulence and deceit.
The political identity of the black man as an unassimilable Other, notwithstanding his actual high degree of cultural and linguistic assimilation, still rules in American politics today.