"you'll either need to use smart editor commands that let you navigate and edit your code based on s-expressions rather than rows/columns, or you'll have to sort out closing parens by hand."
The beauty of parentheses is precisely being able to edit code in meaningful chunks because the parentheses naturally organize our code that way, which is part of why I think Arc's philosophy of "First, we kill all the parentheses" is away from goodness.
When I do edit code as if it were just so many lines and characters (about half the time -- after a dozen years I still have not mastered more than a few keychords) a simple "reformat" keychord automatically puts everything where it should be. And I am rarely disappointed by mistakes because the editor is still giving me cues by auto-indenting when I hit TAB and by blinking matching parens as I type.
I would suggest folks spend a few weeks writing Lisp before they try to change it, they might be surprised how they end up feeling about the parens. Unfortunately pg himself has it in for parens, so I cannot blame you all for the syntax massacre I am witnessing. :) A non-problem is being solved.