To some extent, this was discussed in "The Starfish and the Spider", which is about "leaderless groups". The book praises the power of decentralized, individualistic cultures (that you describe as "Light Side"). However, it admits that they're slower and less-well coordinated than hierarchical organizations (like the military, or some corporations).

You've outlined some of the benefits (recruitment, coordinated action) of encouraging public agreement and identifying with the group. You've also outlined some of the dangers (pluralistic ignorance, etc.).

Possibly the appropriate answer is to create multiple groups, so that each can be a check against the others turning into cults. Possibly even a fractal of groups and subgroups.