I am trying to make a Intranet website for our company with the k2 components.
I just made a category Intranet and put an article in it from the backend this looks nice :)

but how can i make it like this:

When someone logs in they can write/post an article so it will go automaticcaly in the intranet blog category.
The logged in user also can see the whole blog and write comments to different topics.

is this easy or can't it work ?

In k2 options enable front end editing
create a k2 user group - registared if not already there, set the permissions for the group
The user or login module will have a "add new item" link
The user will have to choose the category and save his post