I feel like it definitely comes with that risk, which is why I would treat all the money as 'donations' like a charity where you don't expect to receive anything back... in fact this is a good reason not to give angel investors any passive income because they would be expectant like shareholders and it might foster the wrong dynamic. Really all of the harvested interest should be spread amongst those who actively involve themselves in the community project, whether thats farming, marketing, teaching, learning, playing, receiving produce, the whole lot! Hell even relaxing in a community hammock is worth a few pennies in my book! I want to see people enjoying life in our society, so why not incentivise it?
Back to your question.... it would definitely require some intelligent investment strategy Im sure, especially as this is such a young space that is constantly evolving. We have to be alert to changes all the time, and spreading the investment across multiple platforms would probably make sense, and all the clever things that investors do to limit potential disasters. HOWEVER, have faith! Its been a long term thing on the hive/steem blockchain: 'Came for the Money, Stayed for the community'
By incentivising positive activity, we can actually encourage joyful interaction, which then rewires our behaviours to become more openly compassionate. I felt it happen in myself in the early days of steemit and I think its had a profound effect on my life. Imagine if it was REALised in to our offline community interactions!!?? Sure, when a crash comes around and the money disappears, you would lose a few people naturally, no judgement, but Im certain that many would rally around and put their beautiful hiveminds together to keep this wonderful flame of community alive. Might not work, but hey, if we don't try we'll never know!
In short - the money people put in, they have to accept is a philanthropic donation to an experimental project. No guarantees