I have long thought that a precondition to the continuation of any IP should be that the rightsholder make the IP available to the public on terms somewhat similar to the IPs original publication. So if a game or other work ever goes out of print, the copyright to it evaporates. I think this would be perfectly fair to ensure creators get their payday without depriving the public of access to good old works.

There should be a yearly filling for each copyrighted work, with a fee starting at a trivial amount and doubling each year...

I agree in principle but I feel a doubling may be a bit too steep.

I actually like this. If you start with 10 cents for the first year, it's $100 by year 10, $100k by year 20, and 100 mil. by year 30, around which it becomes impractical for any IP. So a decade for small projects, two decades for commercially successful stuff, and 3 decades for company-driving IP.

Squatter's rights, for IP. If you notoriously develop a new work based on the license, and nobody sues you for three years, it's your IP now.

That’s more or less how trademarks usually work and people generally seem happy with them.