Not too bad of an idea... I'll check in if I could at add that in with little effort :) That could really speed up the progress on the consecutive runs.
Love the idea to give the shadow guy a little more spotlight and an optional ending. If I could, I'd love to have a side quest with an optional ending for every major character, but I'm currently swamped with other stuff. Maybe I'll have some spare time when my other projects die down a bit.