Someone should be able to create a main/parent/etc account and define other journals as alternates/children of that account. If you're logged in as the main account, you should be able to comment as/update as/manage settings for/etc any of the alternate accounts, preferably with inline AJAX that will reload/redraw things (so you have access to userpics, tags, etc) without having to load the Work As User menu and re-input your password