What is the role of research in liberal arts college faculty evaluation?
I believe your list implicitly says this, but I'll include an answer anyhow, because I think this is an excellent question and I am interested in hearing answers that supplement what I write below.

Teaching divorced from serious engagement with the subject matter taught is arguably a very suspicious activity. In principle, if someone is paying a large sum of money to be taught a subject, the teacher should not only be able to convey his subject clearly, but also should be a practitioner of that subject. The living content of a subject is found in the minds of its practitioners, and so attempts to teach even the ideas which are archaic without the living insight driving honest contemporary investigation of the topic is very much in danger of becoming stilted, sterile or, perhaps worst of all, too packaged or neat.

One might oppose this view by pointing out that most undergraduate students do not need to know what is going on at the front lines of any subject, and the historical efforts and ideas, presented clearly in an engaged way, are enough. For cultural purposes, this may be so. However, a passion for teaching at the highest level morally ought to be accompanied by a passion for learning at that level, which is what research or serious scholarly engagement is at its heart.

Another strong argument against requiring research is the following: students at an average primarily undergraduate institution are generally not going to be prepared for graduate study in certain fields, so why should time and energy of faculty be sunk into research in such fields. (Many good institutions with PhD programs also need to remediate entering PhD students, suggesting that this problem stretches beyond undergrad-only institutions.) Again, though, I answer that learning and teaching should, ideally, not be decoupled.

A third argument is that it is possible for an engaged teaching faculty member to learn for his own enrichment and that this does not need to happen at the level required for research or peer review. I can only answer this, unfortunately, by my personal experience and opinion. It bothers me that when a student enters university in order to learn a subject, he cannot tell the quality of knowledge he will receive (whether the community of peers of a student's professor regards the professor's ideas and approaches as relevant). It is our responsibility to ensure that students are exposed, to the best of our ability, to ideas that have impact. I cannot see how to do this without being able to point to peer-reviewed faculty contributions.