Your proposal is worth considering. But Point (4) tells us that ISPs would certainly like to favour certain content creators and curators in whichever way they would be able to do that. And that can be a danger to neutrality.

Secondly, with reference to point (1), what is the provision to pay funds to Amazon in the eventuality of a steep fall of Steem to about 0.00 BTC for a certain period?

I think a lot of thinking and creative input is still required to make this proposal viable. And if you believe that this could be done then why don't you go ahead with it. You will easily get a lot many supporters for your project?