Changing Bitcoin's RIPEMD-160 > SHA3-256 and SHA-256 > SHA3-512

[Dokument]

Would there be any problems (cryptographically) with creating yet-another-bitcoin but using SHA3-256 in place of RIPEMD-160, and SHA3-512 in place of SHA-256?

So SHA3-256 would be used for creating addresses and SHA3-512 would be used for hashing keys. Assuming the only changes are the hashing methods used, would this cause any problems with the functionality and strength of bitcoin? The goal is to increase the future-proof and since SHA3 is out now, I might as well upgrade to it.

I am working on something entirely different (Secure and anonymous mailer/messenger), but this is the premis of a high-level crypto decision. So I am bouncing it off of as many people as I can.

Thanks,
.dok