They're not Literature, they're not high art, they're bubblegum fantasy of the ilk Butcher enjoyed when he was a kid (as those irritating blurbs at the back of the Dresden books state), and as such I think they succeed perfectly well.

The Furies being based on elements isn't cliché; they're the basic things a world is made of so it makes sense. The partnership Butcher created with them is quite nice.

The First Prince being strongest makes sense because he controls an entire country and thus can command the Furies. This is actually explained in more detail further on in the series. So in a similar way, the Lords and Ladies command the Furies of their lands, and so on. Plus personality - strength of will - has a great deal to do with ability/strength of "magic".

Sure, I agree that the books have many clichés in them, but a cliché isn't necessarily a bad thing. It's what you do with the tropes that makes the difference. I like the way Butcher uses the familiar elements of a typical bubblegum fantasy and turns them slightly. Again, things work better when you've read the whole series.

They not perfect - I agree with you on some of the weaknesses in Butcher's writing style, but think they're there to see in Dresden as well. There's enough innovation and political wrangling to make them interesting and worthwhile, though, and that's all a bubblegum fantasy needs.