The first idea, as previously mentioned, conflicts with destructuring. Plus, global variables shouldn't be assigned to much, anyway. Local variable assignment already handles this issue pretty well, with "let", "with" and "withs".
As for the second issue, lists are not a primitive type in Lisp: They are made out of cons cells. I think a "cons" symbol should take priority. Once we have that worked out and it proves useful a "list" symbol might make sense.
