Do I have to accept/moderate every elements?

No. You can disable the moderation feature in your Moderation page.

Disable moderation with LiveTweetApp

However, we think that the main feature for a Social Wall is the ability to moderate content. What could be worse than having a bad tweet being displayed during your event on a giant screen in front of hundreds of people? That’s the story we’ve heard a lot.

We still recommend you use the manual moderation whenever it’s possible for you.

Note: Disabling the moderation can only be done when a Pro Package is active.