Fortunately, so far all the issues raised have been things I previously considered and planned for.
Satoshi:
True, if it happened suddenly. If it happens gradually, we can still transition to something stronger. When you run the upgraded software for the first time, it would re-sign all your money with the new stronger signature algorithm. (by creating a transaction sending the money to yourself with the stronger sig)
Nobody is asking why he did not move and is not moving these early mined unmoved P2PK coins:
https://bitslog.com/2013/04/17/the-well-deserved-fortune-of-satoshi-nakamoto/
https://bitcointalksearch.org/topic/satoshis-fortune-lower-bound-is-100m-usddebate-going-on-do-not-tweet-175996
The only question is:
Quantum computing or solving the "Satoshi Prize Competition".
Nobody can stop that race.