"'Kickstarter could significantly improve things by imposing a cap on the amount of money taken above the original request."

That is your opinion, in my opinion this would be bad for KS.

I don't know why some grow ups people need someone else to put limits on the money the can spend on something, like they are dependent children who need to be controlled what they do with their own money.

Or worse, they want to tell other people what they can spend. They are totalitarian in the inside.

Well, perhaps most people want to use a website that gives some sort of sense that a large portion of their projects aren't over-hyped vaporware.

They could, but honestly they should just be more insistent that project founders make more use of the existing tools. They provide a way to say there's a limited number of awards available at a given tier; if you're not going to be able to scale past ten thousand quickly, then don't let more than ten thousand people sign up to receive the product - at least not from the first round.

Perhaps yeah, it'd have a very similar effect.

It would perhaps also drive up orders early in the cycle, as people can't wait until the last few minutes when they see a project has been funded.

Personally I think the simplest option would be allowing a 10% "overshoot" fund, and beyond that the project automatically closes to new backers - this should ensure that despite the various reasons why the money wouldn't come through from individuals (credit card rejected, etc), a funded project would get it's full amount.