They're good points, ones I've made in the past. But, I think the issues are surmountable.
For example the case of presenting drafts to publishers could be considered to be a certain class of limited disclosure and the works could be treated as still private and non-public. Then a similar system to patents could be used whereby the publication, the [licensed and purposive] presentation of matter to the public domain, would be the key date.
Such a copyright system would focus on the protection of business interests of producers (i.e. authors, etc.).
In parallel I would maintain moral rights on a similar basis to the current copyright terms. They would start at production, last for life + some-years, and cover at least the right to be named as author of your own works and other similar rights that prevent libellous edits being issued and such.
To pay for the system one could use the Statute of Anne's model of requiring payment for a second equal term. I like the 14+14 model; it still favours the author strongly IMO but allows works to enter the public domain when they are still culturally significant (to allow their effect on cultural development to be maximised). A 28 year term isn't quite a full career and so there is less sense that we're dissuading 'artists' from continued production.
Under my formulation the statute would not protect works that could not fully enter the public domain, those with DRM say. To allow companies to use DRM they would need to submit a free-libre copy of their work which could then be released when the term expires (or put keys on deposit that could decrypt the works, or what have you). Copyright is a bargain with the people, rights holders need to uphold their end of that bargain too.
There's much more that I could flesh out, but I doubt anyone would read it here ...