I can’t see new posts/threads or modifications I made to the forum.

If you are using some third-party plugin for caching (WP Super Cache for example) and disable caching for the forum-page, everything should work fine again.

I can’t upload my files.

By default only files of the following filetype can be uploaded: jpg, jpeg, gif, png, bmp, pdf. You can modify the allowed filetypes inside the forum administration.

Where can I add moderators?

Moderators can be added via the user edit screen in the WordPress administration interface.

How can I show a specific post/topic/forum/category on a page?

You can extend the shortcodes with different parameters to show specific content only. For example: [forum post="POSTID"], [forum topic="TOPICID"], [forum forum="FORUMID"], [forum category="CATEGORYID"] or [forum category="CATEGORYID1,CATEGORYID2"].

Where can I ban users?

Users can be banned via the user edit screen in the WordPress administration interface.

How can I add a captcha to the editor for guests?

To extend your forum with a captcha you have to use one of the available third-party captcha-plugins for WordPress and extend your themes functions.php file with the checking-logic via the available hooks and filters by your own. For example you can use the plugin Really Simple CAPTCHA and extend your themes functions.php file with this code:
https://gist.github.com/Asgaros/6d4b88b1f5013efb910d9fcd01284698.

I want help to translate Asgaros Forum.

You can help to translate Asgaros Forum on this site:
https://translate.wordpress.org/projects/wp-plugins/asgaros-forum.
Please only use this site and dont send me your own .po/.mo files because it is hard to maintain if I get multiple translation-files for a language.

Please approve my translations.

You can approve translations by yourself if you are a Project Translation Editor (PTE). Please contact me in the forums if you are a native speaker and want to become a PTE.

How can I add my own theme?

You can add own themes for your forum in the /wp-content/themes-asgarosforum directory (for example: /wp-content/themes-asgarosforum/my-theme). All themes in the /wp-content/themes-asgarosforum can be activated in the forum options. Each theme must have the following files: style.css, widgets.css and editor.css.

Which hooks and filters are available?

You can find a list of available hooks and filters on this site:
https://asgaros.com/support/?view=thread&id=407.