Thanks for the cosign on #3 and #4.
There are tons of successful companies that already run on #2, so you can't treat it as implausible - it already exists. You don't need to have any single way of doing it, you just need to ensure that every employee has a stake or a say, and how the business operates (for example, who to lay off during a downturn) is a decision collectively made by the employees or made by someone appointed to do that by the employees and looking out for their interests, rather than being made by an owner looking out for his own interests. And yes, leaving the company means cashing out your stake and losing your say in the company, why shouldn't that make sense? You still get recompensed for the value you put in while you were there, but you're not going to keep making money off of other people's work after you leave.
#1 doesn't require a government any more authoritarian than our current government, which already necessitates a constant regulation of the money supply and all asset classes. And yes, people WOULD move away from cash into other asset classes, because hoarding cash would become useless. But that's the whole point. It's never been cost-beneficial to hoard natural assets over time because most assets cost money and lose value over time unless you use they actively. If you hoard grain, for example, then it costs money to maintain it and you deal with steady losses over time unless you flip it. Money is complete unnatural in that it gains value over time rather than degrading and costs virtually nothing to store, so money broke the system. A negative interest system would simply make money more like all our other goods - a potential burden to hoard, so that flow is emphasized rather than stasis.
Your idea that it would halt progress is actually the exact opposite of what would happen - in a negative-interest system constant ingenuity and constant moving of assets is incentivized, rather than the current system which incentivizes hoarding. There's actually more process because the wealthy are forced to be more active and the access is more distributed.
If you want to read more, this guy breaks down what's wrong with interest:
The following chapter is from Sacred Economics: Money, Gift, and Society in the Age of Transition, available from EVOLVER EDITIONS/North Atlantic Books. Return to the Sacred Economics content page here. In spite of the holy promises of people to banish war once and for all,
sacred-economics.com
And here he breaks down how negative-interest economics would work:
The following chapter is from Sacred Economics: Money, Gift, and Society in the Age of Transition, available from EVOLVER EDITIONS/North Atlantic Books. Return to the Sacred Economics content page here. Debt can endure forever; wealth cannot, because its physical dimension is subject to the...
sacred-economics.com
Those are just two chapters pulled out of the book, there are other chapters that expound on those chapters and the whole book is fire.