Flat Fee Shipping Range

Sure. It would require a customization, but not a big deal to add X more graduations. To allow unlimited number would be a bit more involved, but not rocket science ;-)

"How to do this" for such a task is probably more than can realistically be tackled as a forum post.  As programmers, our approach would be to identify the page that performs the admin, examine its functionality, then determine the appropriate edits.  Once that is done, you then move over to the shipping choices page in checkout to test it. If you want to tackle this, the above is how you might consider getting started.  Just make sure to retain a working backup before you carve up pages.

I was able to add addition price ranges if any one needs help in the future, I can tell you what to do and send code samples.