Dani:- Autoland has nothing to do with Visibility? Not sure what you mean by that statement? Yes the Aircraft can't see but the Commander sure has to see something in basically all LVP proceedures. ( excluding Cat 3B with no decision ht ) So Visibility does matter........not to mention there is also a crosswind limit for the Airbus Autoland which is considerably lower than the normal crosswind limit.
Practice Autoland does not have to be done in VMC, currency is kept every 6 months in the SIMULATOR during your Sim cycles as per your Countries regulatory agency.
There is nothing to stop Autolands in marginal weather or if the crew feel tired ( for eg ) Just be aware the protected areas are not protected!! Indeed some Airlines recommend Autoland be used even in conditions which technically don't require it.