Your idea is good, but personally I don't think it goes far enough for first timers.
If you're making something small, scaling isn't terribly difficult, if you are making something complex, such as a 3d printer, scaling becomes tricky. The more parts you have the trickier the logistics, some suppliers may not scale as easily, China becomes a minefield, and your timeline may be significantly stretched.
This was exactly what happened to us.
When we told a supplier we needed 180% instead of the 100% we expected, he panicked (but came through). A Chinese company pulled a bait and switch, the test parts worked, but production was swapped to a higher temp item which would have melted our product, then blamed us for the error. We switched to another company, but lost thousands in shipping and higher costs.
Kickstarter is meant to start your business, it shouldn't be an all-you-can-eat salad bar. Make it 80-120%. This gives you a very specific amount of product to plan for, you either get funded and can do it, or you don't, but at least you can properly plan for it. Kickstarter is responsible for some of this problem because of how they highlight campaigns (it's different once you reach your goal) and handle funding (fail you get nothing, so people set it low), this too needs to change. Remember, these people are new to business, some aren't even out of school, we shouldn't be handing them half a million dollars and allowing them to go build a company with no supervision just because they put together a flashy video. It's more than most people can handle.