Traceability for example should kick in ONLY if votes get contested in a way that requires an audit.

It would be great if we could trust the government to do the right thing, but I think we've recently learned the lesson that we shouldn't. It's better to simply not give them the opportunity to do otherwise.

All they need to do is scan the ballot through a machine that can read the blockchain, and everyone's anonymity is compromised, as that blockchain is already associated with an ID. This could be done quickly and in secret without the public's knowledge or consent. As we already know, this government of ours takes every opportunity, even illegally, to collect all known information on it's citizens in a pursuit of power.

Obama already weaponized the IRS against political opponents. These lists that can be made from this data will only lead to worse outcomes in the end. Even the knowledge alone that your vote is not anonymous to the government will affect votes and be unhealthy for a republic.