> forget about the shutting it down and think of something actually realistic.

Why is it not realistic? Small teams do excellent work. Keep your team small and trusted. Only accept contributions from your team, and people outside your team who are personally vouched for by someone on your team. It's like climbing mountains or sailing or any other type of inherently risky activity--you don't go out with people you don't trust. It's eminently possible, you just don't like the idea of it.