Amir,
Coming from a community with not much volunteer force, I actually want any strategy which involves minimal human interference into the tagging process, as we can't afford to spread our thin line.
Your first option looks more inclined to what I was trying to say. However, I understand that there will be possibilities of errors or ambiguities and need some level of human check system anyway.
Personally, I would love the third option but looks like it requires more engineering than the other two, forgive me if I am wrong. So considering the lack of initiatives in this area in the past, I would stick to the first one as a more practical approach for now.
Regards,
Bodhisattwa