First, and in general, you are missing a couple of very basic things about economics. Due to our nature as humans, competition alone isn't the magic ingredient of economics. This is a basic misconception I run into all the time. To have, what would properly be termed a free market, there needs to be adaquate regulation AND cometition. Or, to put this another way, no regulation equals anarchy, not freedom.
Second, there are reasons we have things like utilities. Notice that our roads, our water and sewer systems, the power grid, basic communications systems (*caugh, caugh* a key here), etc. have been designed as utilities. This doesn't mean that they can't be private, but they need proper oversight and regulation, to ensure certain aspects remain intact for the best public interest.
Third, I think you've missed one of the key points behind Net Neutrality. It isn't a particular regulation, but a PRINCIPAL which is absolutely crucual, however we choose to implement and regulate it. While we can argue over what, if any level of traffic shaping is necessary (say, for emergency communications, or core reliability, etc.), what we don't want is an ISP partnering with a government or content provider to favor or censor content for financial benefit or political interests. There is a 'cloud' of data end users want to access, and the 'pipe' to that 'cloud' should be a 'dumb' as possible, while *maybe* making certain exceptions, only for very important reasons (but, even that opens a potential can of worms, unless done with great public transparency and consideration).
Fourth, sure more competition would be great. However, I'm failing to see how a few powerful telcoms partnering up with content providers to draw customers to their partular flavor of the Internet is going to do this. I see nothing but bad for the end users coming from such an arrangement, if not downright evil... ie: the end of free-speech via the Internet. If you don't think that could happen, you're simply naive. At least keeping that possibility illegal, increases our chances of not going there.
Fifth, you speak about the cost of over-provision. While you're technically accurate, I think the problem is in scales of magnitude. Wasn't it the Comcast CEO who recently made the daft statement that they have so much bandwidth they could unleash, but their customers wouldn't even know what to do with it? Really? Cellular data aside, the Internet end-mile is SO far behind in the USA (despite $200B in tax-breaks we've seen little benefit from), that what you're speaking of isn't even an issue. I think I read that we're talking like $0.02 per/GB of data as the cost... and many say that's high these days. What does the average user consume? 20 GB? 50 GB? That's like $0.40 to $1. Maybe the *big* user uses $10 or $20? Big woppie! They are charging $60+ for crying out loud! This whole push (and why telcos are so adamently opposed to Net Neutrality) is over their want to add another layer of profits onto their business model, and shape the Internet to their financial benefit to win customers from the competiton. If, say AT&T, provided the best access to Netflix and Google, who's going to go with Comcast if they enjoy those services? So, it's exactly anti-competition which is the goal here.
If they have no problem dealing with regulation, as you say, why are they so opposed to it? Why is it telcos vs nearly everyone else? Heck, when the Christian Coalition and the ACLU agree, along with most of the tech industry innovation leaders, shouldn't we, maybe, pay attention? (How often does that happen!) Especially when it's just one group of monopolistic businesses on the opposing side of things?