> What's your current mental model of an "ideal Lisp"?
> It would be something like a fusion of Clojure and Common Lisp, (...)
Mine would be, too. Unfortunately, that's not possible. Clojure is one of those few languages actually designed by somebody who knows what they are doing. Clojure's limitations come from the limitations of the platform it is running on and certain design criteria (interoperability) that were necessary for its success.