Hello David M! I will answer a few of the questions that I feel able to answer clearly, but I will ask others from DFINITY to chime in as well for other questions.
As stated, these interim rewards will not kick in until the original 48 months are up for each Gen-1.a NP. For a few, this is 11/30/24 (so the final reward distibution for them would be the Dec 2024 distribution), and for the rest, it is 1/31/25. Thus, there is a lot of time for NPs to make plans.
This is fleshed out in these two forum posts:
We believe that 750 is all that is needed, and this DOES include the need for spare nodes and nodes that are down.
It is clear that, for tokenomics needs, the community wants to see extra nodes exit so that rewards decrease, thus helping the token price to increase. The hard cap of 42 nodes per NP will result in a minimum of nodes exiting. The rewards scheme being proposed will reslut in “extra” nodes beyond the 750 which remain on anyway costing the IC less than the nodes that the IC actually needs.
This is a reflection of the common desire for node rewards to reflect the needs of the IC as much as possible. The IC needs NPs to own fewer nodes. Thus, a remuneration calculation that rewards NPs more for a smaller number of nodes is more reflective of this than a flat calculation.
The servers are owned by the NP, not DFINITY. DFINITY does not have any authority or desire to influence what any NP does with their extra servers.
I will ask some of the others to reply to some of your other questions.