Though the general settings of this plugin meet what I want, for the RSS I wished it supported this plugin: Feed Key
For us it is important that the audience is able to retrieve the RSS feeds without any login obstacles. A 40bit hash key as a parameter for each user would enable the user to see in Outlook or any other RSS Reader all what he's allowed to as if logged in. There shall not be any Login required as the RSS software or modules not all work well with that.
Apart that this scares the audience to use RSS at all.
Please allow the Feed Key plugin to work with this plugin.
Otherwise I am doomed to open all RSS feeds for the time being.