Let's go further and tax it. If it's still worth something for you after X years, claim it, but also pay the tax. When calculating piracy damages, use the same value as what you declared as taxable. If you want society to defend your rights, pay for it.
Not a bad idea - some entity must show legal ownership via chain of custody and make a claim every year, if they can't do so, it becomes public domain with an extra 1 year grace period or something.
No, it should be non-transferable (but commissionable, so that companies can still own copyright if they paid employees to generate works), have a fixed short term (say, 20 years), and should be voided when the copyright holder expires before the copyright itself expires.
