[Ethereum] Can you update contract token decimals and token name?

Visit their Feedback Page:

1. Make sure that your token contract's source code has been properly verified on their site.
2. Provide them with your contract's address.
3. Provide them with your website's url.
4. Provide them with a link to download your 28x28 PNG icon/logo.

Then wait... There's no guarantee that they'll add your info to their private database.

There's nothing you can do to avoid this. That is why you will see most ICO owners go the extra mile to communicate the exact address someone should be making a transfer to. You can't trust neither the token name nor the symbol, only the address.

There was a proposal going around for building a registry of token names/symbols so they would be unique, but I don't know where that stands as of this date.