This is exactly the mindset that leads to the patent system we have today. You are thinking of intellectual property as an idea - its not. Meaningful intellectual property is a functioning method or product that delivers value to people (is this all IP? no, but this the scope of IP I am suggesting protecting). It takes, research, communication, testing, experimentation, failure, and repetition to truly build something that works. And yes, forensics will show the hard drive state and web history logs before, and after you were in the shower and then all the way along the long road to you building something that people actually want.
You hear of an existing product? Who cares? If you can invent something similar without referencing related documentation or code during the actual process of invention keep it out of the legal system.
What leads to the patent system we have today is greed and lawyers. If the system can be exploited to legally steal buckets of cash from successful companies, then it will happen. The mindset of the industry seems to be overwhelmingly opposed to this, but that doesn't matter as long as the law permits it.
A new kind of certification for complex and novel inventions will not solve anything, because it's the simple and obvious inventions that everyone depends on that expose us to patent attacks.
Well, I started with the idea of 'We should be free to invent' - thanks for taking the time to poke holes in one proposal towards this end. I tend to agree that it would be difficult to build a practical certification system, at least with any proven system we've seen today.
Our government provides us many freedoms in the constitution, perhaps an amendment is a better proposal. That way the courts can interpret a more meaningful definition of Freedom to Invent as a way of shaping the current patent system.
You hear of an existing product? Who cares? If you can invent something similar without referencing related documentation or code during the actual process of invention keep it out of the legal system.