For the sake of a handful of older profitable works, all works will forever be held back from the public domain. Better that you concede Mickey Mouse and let the rest benefit society as public works.

I agree, but my proposal is one that is much more likely to get through than the all-or-nothing approach.

And yet there are multiple literary, movie and TV adaptations of all of those characters you mentioned that were not created by their original authors. Not to mention the tons and tons of crappy fanfic that nobody reads (except me, apparently).

Also, let's not justify the desire for having things for free by calling somebody's artistic labor a "cultural idea" and implying it should be made available for free. If you find value in something, pay for it as the creators wish. If you wish to build on top of it, license it.

How far back does it go, and how far forward to creators' monopolies last? Should a license fee be paid whenever somebody references War of the Worlds? How about Shakespeare?

Small-budget adaptations should be possible, as well as large-budget.