Not an altcoin.
It would be an altcoin.
There are some early addresses
They are using P2PK scripts where the output contains the public key instead of the hash of it and there is no "address" defined for these scripts, they are just outputs without a corresponding human readable string (aka an address).
so those coins can be stolen if enough computing power is put to them.
If by enough you mean a million+ years worth of computing power, then you are right.
Also your argument do not justify your idea simply because if ECC could be broken and bitcoin were still using it, then it would become obsolete as a whole.