How can I change the logo on the projection screen?
To change the logo displayed on the projection screen, please read this article: Where is my Wiz customization page?
How can I display only the most popular questions in full screen mode?
You can display on the projection mode the messages that gave rise to the most reactions. Discover how to do so in this article: How to use the reactions?Note: reactions can be positive or negative, therefore top messages will be the most reacted...