Perhaps the "not a word" business has the slightest rhetorical overkill in it. But really, not much. Is it not true that Lincoln utters not a word in the debates whose purpose is to make an economic point for its own sake? Do you think the text you posted is an exception to that statement? The immediate context of the remark you cite makes it clear that Lincoln is only talking about it in order to convict Douglas of inconsistency in his demand that Republicans accept Dred Scott. There is not even the slightest aside about the bank issue in itself, of the sort: "which decision, by the way, I support."
I'm all for being fair, but it seems to me on the question of whether Lincoln discussed economics as a point of debate in the Lincoln Douglas debates, the answer is simply and absolutely, no.
Please don't think me grumpy about your post. I just don't think we need to help DiLorenzo escape from the being convicted as an absolute liar on this point.
It's funny that we were typing our replies simultaneously.
DiLorenzo's squirming on this reminds me of the old anti-Catholic joke regarding the Jesuit who was on trial for killing three men and a chicken, and in his defense, triumphantly produced the chicken, alive.
Cheers,
Richard F.