Now, let's read what theymos wrote when he created the self-moderation feature.
In most sections, you now have the option of marking topics self-moderated when creating them. In self-moderated topics, the OP can delete replies. The option for enabling this is under "additional options". Topics cannot be converted to self-moderated topics after creation.
There are no rules to self-moderation. In self-moderated threads, replies belong to the OP. In other threads, replies belong to the respondents individually. Think carefully about whether you want to reply to a self-moderated topic, as your post may not be given due respect.
Tell me if there are any bugs. If this ends up not working out well, I might remove it.
1. What is the extra benefit of this topic?
For good purpose, to delete spam posts. For shady purpose, to censor posts that are harmful for OPs.
2. Can a newbie make such type of topic? If not then which Rank require to make this type of topic?
Everyone can create a self-moderated topic but you have to do it at beginning. If you create a non-self-moderated topic, you can not change it to a self-moderated one.
3. If I use "report to moderator" option in such type of topic then where to sent my report?
The moderator who is in charge for the board in which that topic is made.