This makes no sense, we have an edit button? Usually if a member spots something they missed on the first read through they edit there post and reply, "EDIT : Oops Missed xxxx ,Sorry". I know I've done it a few times when I've been reading a long piece of text.
Can you explain to me how this would limit your freedom in anyway, unless its something blindingly obvious that I'm missing I don't see how any freedom is lost at all?
I think something like a "Merge replies" button or just an automerge feature would be a great! It would cut down on those annoying multiposts, and stop excessive multiposters from double posting! Automerge! Automerge!