I've been doing a little online searching, nothing serious, but have noted that many sites and slavery/reconstruction experts dismiss these claims of slave insurrections and abolitionist incitement, out of hand.
HOWEVER, they do confirm some of these instances of abolitionists being arrested in the South attempting to stir up problems. I am a little distrusting of modern researchers and professional historians, when it comes to a storyline that is in opposition to their ideology.
Finally, if there was only limited activity of this kind, but Southerners universally felt they were under attack or on the verge of an abolitionist (Lincoln supporter) incited insurrection, it cast a whole different light on the South's response to the election of "old Abe" and their fears for their families and property.
Does anyone see a connection between this radical abolitionist activity and modern terrorist fears? I wonder if the abolitionists of the time, openly condemned attacks on the Southern civilian population or did they encourage or sit by quietly and lend support by their silence? For many, in the North, John Brown is considered a heroic figure. With John Brown's raid and his aims so fresh in Southerner's minds, it would be reasonable for them to be very fearful (terrorized) by the thought of radical abolitionists and escaped slaves targeting their families and property.
I think this might deserve a little more research to determine the scale of the events and the mood of the Southern people.