How important is it for us to know that in the Old Testament charging interest on loans was forbidden, and that in the New Testament we are commanded to let no debt remain outstanding except the debt of love (Romans)? If you pause and think through things for even a moment you will realize that our capitalist system of economics and finance is quite antithetical towards Christianity. Or at least, that's what the initial analysis would suggest.
How important would it be, then, for us to take a stand on interest on loans? It would be quite irrelevant unless we were able to live without loans (in our modern society), or if we were setting loan rates - in other words, if we were Christian economists. As a Christian I want to do what God desires - as a non-economist I simply don't know what that is in the field of economics, and I don't have the time to find out. Therefore I trust that God will convict me of anti-Christian economics when it is important enough for me to deal with, and that His grace is more than enough to cover it in the mean-time.
The reason the cr-evo issue seems more important than the interest on loans issue is because we as a civilization have hopelessly prostituted ourselves to science and technology - yes, even the church, and yes, especially the creationists. But if we lived in a world where economics was considered more fundamental than science, in which children were taught before they were 12 about J.P. Morgan and John Nash instead of Einstein and Newton, in which high schools run simulated stock markets instead of chemistry labs, then I have no doubt that there would be an American Economists' Association explaining why economics dictates that usury on loans is simply necessary and we should re-interpret the Bible in light of that - and there would no doubt be, instead of Answers in Genesis, Economics in Exodus or something such.
I personally think that the issue is not important unless you are either undertaking a serious exegesis of Genesis 1-11, or you are a practicing Christian scientist. It is far more severe in the latter case because the cr-evo discussion then is not just an isolated discussion; it is often a litmus test for your views towards how science works with God as a whole. It is not literalism towards Genesis per se that turns me off from creationism, but the fact that if I adopted the underlying beliefs they hold (most notably the tendency towards a God-of-the-gaps defeatism), I either could not be a Christian or could not be a scientist. It just wouldn't work.
But if the person I am talking to is not a scientist then I don't consider the origins issue very important (unless, of course, s/he is making a big deal of it). There are far more serious defects than creationism to be corrected in the Body.