Patents allow for the knowledge to be documented and the patent has a limited term after which anyone can use it. Without patents, more things would be kept as a trade secret.

The majority of things in patents could not be kept secret. What we end up with is disposable products because every part is patented so you can't make replacements or other devices that are compatible.

For most things, feel free to reproduce patented parts for your own consumption, just don't give them away or try to sell them.

Thats a non answer. I don't have metal working tools sitting around in my shed that would let me whip up a replacement part for things. As a society we throw away so many things because they contain patented parts and the original company wont sell replacements or they sell them at enormous prices.

Hopefully in the future metal 3D printing becomes common and cheap so we will be able to source replacement parts from torrent websites.

Then what incentive do I have to spend money and innovate when everyone else can capitalize on it? That comment is a demotivational one for innovation in that it doesn't reward the entity that spend time and resources making it a reality.

Inventions could be publicly funded and then the findings be made available to everyone. We already pay for all the inventions we use indirectly so why not just fund them to begin with and actually have access to this information.

That's what academia is for. Perhaps we should ensure that academic research that is publicly funded doesn't end up with IP restrictions placed on it, and also expand the range of research academia engages in, to include more applied-research stuff and rediscovering/popularizing existing know-how that often is not publicly documented and might not even exist other than in tacit form. (This expanded scope for research would also help reduce waste due to academics overcrowding into a few über-popular fields of research, and largely duplicating efforts while trying to "scoop" one another.)

Of course, tacit know-how and first-to-market advantages will always exist to some extent. So, in a sense, we can't fully get rid of "IP"-like dynamics. But we can, and should, mitigate them.

And where are these unlimited funds you speak of? I have a few crazy ideas of my own, that I'm willing to pursue on someone else's dime.

We have the ability to automate almost everything needed for life. It seems realistic that you could spend all your time working on crazy ideas and cost no one a minute of their time.