User right management for categories

Hi,
I alredy red and tried a while but don′t get clear with user rights settings and need some help.
My target is the following:
I have 5 different categories,
Category 1-4 Articles:
– are visible to all users
– can only be posted by editor
– comments are NOT allowed
– “posted by” should be hidden
Category 5 Articles:
– are only visible to registered users when they are logged in
– can be posted by editors and registered users
– comments of other registered users are allowed
– “posted by” should appear

Further the dashboard for registered users logged in should be kept as simple as possible without access to media libary, etc. They should just simply add articles to the allowed category.

How can I reach this target? Which settings are necessary? Do I need any further plugins? Which do fullfill this features?
I have installed the UAM User Access Manager Plugin but have doubts if this fullfills all those needs.

Thanks for your help

Alex