@zetmouse , we've added the @nicename to allow people find members nicenames and @mention in post, like I did it here. This sends you an email notification with "You've been mentioned in forum post" subject (if you're not subscribed here). If you remove this line, people will not be able mention other people in your forum.

In any case, we've added new option to disable this in next version. Please wait for wpForo 1.4.4 it comes in a few days.

Please read wpForo documentation to understand what are you currently using and what should be displayed and what shouldn't. wpForo has three forum layouts. You're currently using the Simplified Layout. It doesn't have post number information. Check those Forum / Topic / Post lists layout and style and decide which is good for you.

https://wpforo.com/docs/root/categories-and-forums/forum-layouts/