I think that having "outlandish" ideas is a benefit in engineering. At certain points in history, all engineered products were at one time, an outlandish idea. So with that said, if someone ridicules you for having a seemingly dumb idea, try not to pay attention. Obviously, common sense will take its toll on your idea, but you never know what kinds of inspiration your idea may cause.
I don't know much about "muscle" wires so I can't comment there. I'm failing to properly remember the concept of the shoes in the back to the future movie. I'm thinking of a more linear concept where the shoes are sinched down (similar to the old velcro shoes). I think designing muscle wires to perform the complex looping of common shoe lace tying would be extremely difficult. If you could accomplish that, then you belong at MIT.
What if you design a system that would sinch the shoes up (as stated above). I'm thinking of a zipper tie type of concept, only more complex with a release and locking mechanism.