Yes. You can use your profile name instead of your email address.

To post on the suggestion board under your profile name, sign out of Yahoo!, and sign back in using your preferred profile name.

To create a new profile name, go to your Yahoo! Profile page, and click on "Edit/Create Profiles" on the right. When you're done, sign out of Yahoo!, and sign back in using your new profile name.

You also have the option to anonymously post comments and suggestions.