How can I see the name of the participants on every message?

You can know the identity of every participant posting a message on your Wiz. To do so, you just need to enable the Identified only Participation mode in the Settings > General section.

Once activated, your participants will have to be connected with a Wisembly account to be able to interact on your Wiz, and all contributions will be signed. 

Note: the anonymity of your participants usually is one of the main reasons people say whatever they think without restraining themselves.