I would ask gsmarena to go for 2nd option but link to email address rather then Facebook
I believe the third method is the best one.Although there will be no previous records but there is no point in keeping wrong information. Start from the scratch.
the same with registered users. AndWhat about starring system for non
voting should definitely be limited to logged in members, this will help save lot of issues
None of these are methodologically sound alternatives. I say this as an academic doctor with significant social science experience. If you want to retain credibility you need to find something better than these options. Consider if you even need a voting system at all. It is unlikely to change opinions. Quality reviews and allowing people to make up their own minds might be a somewhat sounder strategy.
I like system under number 2., but you should add option to login from Google+ and Twiter beside only Facebook