Well ideally you'd fund the development of the product and make profit off of it before launch if you really needed to, either through crowdfunding campaigns, or joining a monthly donation that puts out movies every however many years that are free for all. If a studio or artist puts out bad shit, or puts out something that already existed but just in a chopped up form, people would probably just stop paying that studio or that artist since their credibility would plummet. You could even just rig up a new advertisement scheme as a way to pay creators, which I assume companies would do since they've done shit like that with YouTube.

I also don't understand your hypothetical here. If Disney puts out a new marvel movie, why the fuck would you make another (presumably) marvel movie that has the exact same script? Likewise, why would Disney copy the script of a fan movie when they could just pay pennies to some put upon Hollywood writer for a script? It's not like good scripts for movies are really in short supply, and most problems with movies are like that, they come down to shitty executive decisions. Disney's probably not gonna "release" a chopped up version of your movie that they made for pennies. How would they even monetize that in a post IP world? Why wouldn't people just watch yours instead, if they did that, since they're probably accessible through the same avenues in a post IP world? How would Disney not lose all credibility as a company, as a content producer, as a creator of art?

In any case, if Disney wanted to copy your short film pretty much beat for beat, they could just do that and get away with it pretty much whole hog right now. What are you gonna do, sue Disney? How would you prove that they copied you? Disney's not stupid enough to just copy and paste the same script, much like you shouldn't be, they'd change the words, change the aesthetic, etc, making it much harder to prove in a court. And there's not really a way to solve that problem with more bureaucracy, unless you're totally changing the economic structure, which I'd also be onboard with.

This isn't even getting into how IP works for pharmaceuticals or more important shit. A lot of people died from COVID in African countries because Bill Gates decided to poop his pants over IP law, plenty of people constantly cite the evergreening of insulin.

I dunno, somehow Disney's brand didn't plummet after mickey mouse went public domain, and I'm sure they're gonna continue making more mickey shit in the future.

I also don't know how much it costs to put up a streaming service, but I do know that straight up right now I can watch anime for free with no ads and a better end user experience than any of the mainline streaming services. I can also do that to a lesser degree with basically everything except pro wrestling and other live sports content, because nobody gives a shit about those apparently. Except for AAA and CMLL and lots of foreign promotions which are free on YouTube for some reason.