Kickstarter is fun and can help, but if you want it to be successful it needs to be driven by some kind of publicity, e.g. social media, and preferably drawing from multiple interest groups. This board is one source but the readership here isn't that big. It would be better if you have somewhere else to draw from as well.
Character stats could be an easy stretch goal. You might also be able to make or commission character art as a stretch goal, which could serve a double purpose as cover art etc for Shadow World products in the future. Signed bookplates aren't too bad either, I would do that as an add-on or premium rather than a free stretch goal.