We see the same sort of thing with patent trolls - if all you do is buy up IP and then sue someone, that's not a model that furthers humanity or IP creators.
Any law like like that would be circumvented through creative “leasing” of royalties.
Individual copyright: 25 years or date of death + 10 years.
Corporate copyright: 25 years.
a) That +10 years after holder death no longer makes sense
b) Corporations would be unable to posses copyright.
a) Is a clear and simple exception, that permits inheritors to receive proceeds of a work for a limited time. It would prevent the abusive control some estates have over copyright decades after the creator's death.
b) Intent seems rather like the clauses for code copyright many of us have had in contracts of employment. IANAL but I'm sure something could be drafted that limits transfers but still allows design companies assigning copyright of the customer's new logo. Perhaps the only transfer can be limited to the first three months after creation or something.
Should I have to pay to avoid having those posts become public domain within my lifetime and I lose control of what I’ve written?
A reward system for content creation by definition has to be a pyramid scheme, due to the need for the general public to have examples of normalized contrasting quality in anchoring supposed worth as well as the need for the governance structures to have a well diversified orchard of luscious fruit ripe and especially bountiful enough to cherrypick which works are most applicable for promotion at any given time on the carousel wheel of policy.
There are countless artists and authors who go undiscovered for years before having a breakthrough and becoming popular. There's a lot of non-fiction books that are slow but steady sellers for years. Some of that non-fiction needed years of research.
Drop copyright to say 5 years and you hurt all of those creators, potentially quite badly. The Disney's, George Martin's and JK Rowling's of the world would be hurt vastly less as so many of their sales are right around release.
If I had to throw a number out I'd go with something like 20 years, and upto 5 or 10 years beyond death - to cover those writing an autobiography or creating something in their final years.