Perhaps such a system would work better if scores were on a scale of 10, but even then you have to wonder about the inclusion of some of the criteria, such as economic freedom. What does that mean? Does a country that supports free enterprise (i.e. respect of private property, businesses, etc.) but not free markets (i.e. protects its market with tariffs or quotas) have economic freedom or not according to this ranking? Is a country that supports religious freedom but not political rights (for instance Tunisia) freer than one that discriminates against some religions but has more political freedom (for instance Egypt)? Does religious freedom just mean tolerating other religions, or also accepting religion in politics? Does a state that officially controls the majority religion and religious institution (most Arab states) really have religious freedom? Does it matter if you have elections and political parties if the scope of political debate is severely limited? Does the economic development of a country matter for its democratic nature -- for instance, isn't Mali poorer than Egypt but at least in some ways more democratic than Egypt? These questions lead me to think that it's not worth quantifying democracy, at least not in this way. Rankings are most likely to be used for political purposes than anything really constructive.
That being said, it remains desirable to have a system to compare countries. I would choose to focus on political and civic rights over economic and social ones. But perhaps the most important sense of how democratic a country is not its actual state of affairs but its apparent willingness to mend its ways and the progress it is making -- in other words, a dynamic indicator based on whether there's been improvement in each criteria rather than the actual status of affairs. One could also include a reference to the gap political expectations (based on government promises and opposition demands)on democratization vs. what's actually been carried out. On such a system, Gulf states that have had elections in the last few years would probably score well, whereas Egypt and Morocco would not do so well. That may be unfair, but as a measure of political commitment to democratization, it may be more useful.