"d. Voters encrypt, sign, and broadcast a
Ballot which contains their Votes and a new public key (for which they have the
corresponding private key)."
reveal the private key used to encrypt their votes in (5), allowing these votes to be
decrypted and read into the consensus algorithm. "
This suggests you're using standard public-private key cryptography, so it's really unclear from the combinations of your examples whether you suggest using symmetric keys (which have the problems I posted above) or pub-private key crypto. If you are talking about pub-private crypto, you encrypt using your public key, making it so I can share my vote with anyone... which is solvable with Zack's solution. You do not encrypt using your private key...
Moving on to your FAQ:
"Ballots are encrypted, and contain a new destination (public key), for this reason. Votes are cast in one period, and unsealed in a later period (during which no new votes are cast). Because private keys are required to decrypt, it is always impossible to prove that you’ve voted a certain way"
Here's an easy way to prove you voted a certain way, allowing one to collude very easily (unless you use zack's soln.):
1) I publish my encrypted ballot using my public key
2) I publish the unencrypted ballot, my public key, and any random person can take the ballot, encrypt it with my pubKey and see that I voted a certain way. They don't need to take the encrypted ballot and use my private key to decrypt it to discover my vote.
A solution from twelve months ago that fails to take into account the basics of public-private key crypto is also slightly disturbing
If you do have a solution, and can explain it in a step by step manner that's consistent and doesn't mix asymmetric + symmetric crypto and doesn't involve encrypting with a private key, please explain it as I'd like to read it.