There is nothing wrong with your points, I would just like to add to #3:
You will be surprised that I am actually in favor of managing the heat of the economy and make it accessible to as many players/owners as possible over time.
I am just hesitant that an upper rail, once implemented, gets misused by whoever decides about the price and that it gets set too low.
We are now deep into economic design discussions, which I wanted to avoid, but we can treat it as a thought experiment:
What if we don't let the DAO set the upper rail price, but let it come down like in a reverse auction.
This would mean a free market in the beginning, which is ok for our current target audience, which is mainly web3.
There will be price swings and speculation, but we are here for the long term and can accept it.
You accept the free market price and have a higher chance of finding these rare Illuvials or wait (many days or weeks) until the upper rail comes down and gives you the unlimited fuel for a fixed price option at a price you like.
Along with the upper rail price curve coming down, there would be the fuel production curve going up. Both make it easier to pay for the Overworld as time progresses.
Until the market price reaches a point when you play Overworld almost purely for fun, because it has become so cheap, but you still have a (small) chance to find that rare Illuvial and get rich.
This would be like the land sale reverse auction, except that you wouldn't mint the land as soon as you accepted the price, but would get the chance to play the OW.
Again, not a fully designed economy, just a suggestion for setting the upper rail.