I propose deleting all but the last 1000 blocks. this will keep the blockchain small and lean. as blocks build upon each other, older blocks are not needed. The only problem with this is if there is a 1001 block chain fork which shoudl not happen.
Learn more about how a system works before you start guessing at ways to "improve" it. Otherwise, your guesses aren't likely to make very much sense.
I propose reducing the energy released in a fission reaction. This will keep the temperature of the reaction down, and make nuclear energy far safer. The only problem is if there isn't enough energy released to be cost effective.