Maybe I'm missing something here, but I'm confused... How would getting knowledge of a public key be even remotely dangerous ?
If the hashing algorithms are broken I might be able to generate an ECDSA private/public key pair where the public key hashes to the same bitcoin address as one of your public keys.
If I can do that, then I can spend your coins.
On my list of things to worry about, this is just below "Asteroid impact destroys the earth" (but above "Aliens invade and make me their slave").