I've figured out why Raul just stands there in the Lucky 38. In the GECK, it turns out that his Lucky 38 AI package was set to "travel" instead of "sandbox." Just switched it to sandbox and no more wallflower! I've made a mod for now, but hopefully, Bethesda will take notice and fix it next time there's a patch.

You can download my fix here: http://www.newvegasnexus.com/downloads/file.php?id=41756