No, please don't add a library function for infix operations. I don't think it adds anything to the language other than clutter, and it becomes basically a crutch for those new to lisp that will just make it harder for them to transition to the lisp way of thinking.
wow, good catch. Pretty sure it's not on purpose though. That syntax defies everything that dot notation means. Consider it supported for the same reason Arc has UTF-8 at the minute.