Whether it's a hostile board takeover, or a bad hire in a CxO position (or even any regular employee with influence), those risks exist everywhere.
Actually, I think a co-op is better protected.
A co-op should have founding principles, and acting against them should raise red flags.
For distributing profits, etc, again, standard legal docs. Here in Quebec, there are orgs who can help with that (reseau.coop).
The biggest challenge is growing: I'm in a 5 person co-op. In a previous life, I was in a 25-person collective which became hell to manage, as everyone wanted to be heard, but few wanted the responsibilities.
So in our current co-op, two of us tend to enforce the bottom line, in our respective areas. I mean, legal structure and org structure, while there may be influenced, can be pretty orthogonal.