Agreed. I also propose redesigning 3-stage rockets so that the top two stages carry payload and only the bottom stage carries fuel. That way twice as much could be carried into orbit for half the fuel. I am surprised it wasn't done like that for the manned space program.
We better make the speed of light higher so that optic fibers can allow much faster data transfers
I think we can achieve both of these by first making space-time riemannian instead of Pseudo-Riemannian. With euclidean space-time there should be no need for pesky limits like a constant speed of light, and the extra payload mass should be offset-able by simply moving some of the fuel you didn't need into the past.
ObOntopic: While not all nodes need to constantly store the complete history it is not so simple as waving some hands and saying "just keep X blocks": access to historical data is important to Bitcoin's security model. Otherwise miners could invent coins out of thin air or steal coins and later-attaching nodes would know nothing about it, and couldn't prevent. There is a careful balancing of motivations here: part of the reason someone doesn't amass a bunch of computing power to attack the system is because of how little they can get away with if they try.
To achieve all aforementioned goals at one fell swoop, and then some, we should simply nullify the 2nd law of thermodynamics. Without this pesky restriction, we would not be faced with mortality and therefore would feel no need to rush to any accomplishments at all.
Since we do have the second law, however, people will also tend to lose track of their wallets, ensuring that even if hoarding were somehow discouraged or even eliminated, there would be accidental unspent coins.