I don't have kids so am looking at this "in theory" only.
From my perspective, going down the licensed character route cheapens the concept.
I see what you've done so far, and there is some great aesthetic and functional design ideas in the project. While I realize it's not exactly what you are doing, but slapping a cartoon character on it to me screams "Sell-out, cheap". It also might appear that way as a portfolio piece, something to consider. These days liscened characters are put on everything with very little regards to brand/fit, I don't really see it as a design "plus". see the topic "What is it with Nike, anyway" for more on that....
...IRL, you'll have plenty of time to do those high volume, commercially driven products - why not do something different for a school project?
I do know there are a lot of licensed character footwear out there in the mass market (wal mart and all), but I see your design as a more sophisticated product, one for more discerning parents, esp. if you do go any "green" route in materials/construction.
I'd encourage you to perhaps re-think the idea... perhaps look more into high end toys like Brio, etc. I see your design as more appropriate to this market. something akiin perhaps to SoftStar http://www.softstarshoes.com/
and some of those other "premium" kids products... Not cheap, but a good solution.
I know a lot of parents, esp. of my own and a bit older generation who do everything possible to avoid branded items for kids. They value quality, design, and function (what seem to be your key drivers) over the traditional kids' object values of cheap, disposable and flashy/branded/marketing-tie-in.
another angle if you still want to veer into this area, might be to develop your own characters. You already have the eyes/teeth, why not create some of your own characters.
this is some good inspiration -