I will answer to my own post with some ideas

Idea 1

An option to receive email updates and alerts if something that you define happen. For example, a friend posted something in a tag that you are interested in.

Idea 2

Auto vote if some users (of your choice) post something new (post) or (comment) as an option in the tags (or not) of your choice. (yes we can do this)

Idea 3

Option to hide every post and/or comments from users with a rank of X (><). Example : Dont show posts from users with a rank of less than 25.