I might go so far as making the platform invitation only. I think doing so would provide two benefits. First, it would allow you to generally restrict the userbase to the type of person for whom it's intended. Second, it provides a sort of crowdsourced verification that I think would help people feel like they're part of a trustworthy community.

This is perhaps comparable to private torrent trackers that are invitation only. Though in this case, there wouldn't be a strong incentive to abuse that system. Another example is the invitation-only system with which the OnePlus One launched (and still uses to a degree). The One started off as a "flagship killer" geared toward tech-savvy people, specifically the kind of people who would not buy an iPhone. Like with many "exclusive" products, people became interested. The simple fact that you could have offices at large tech companies with mailing lists with the sole purpose of distributing free invitations is not only excellent advertisement, but it demonstrates how making a product/platform/service exclusive can have substantial benefits when geared toward the right group of people.