pospiech wrote
However now I would like to change these setting in such a way that everybody can read the wiki, but changes require a login.
What needs to be changed to get this behaviour?
Have a closer look at
http://wiki.splitbrain.org/wiki:acl there you`ll find all the information you need.
pospiech wrote
Additionaly, is it possible to allow logins without password?
No, but you could set the ACLs for certain pages/namespaces so that everyone can edit them, that`s nearly the same as allowing passwordless logins ;-).