The problem with both of those ideas is that too great a risk and people would simply never use the option. "Here's a 1% chance to completely kill your entire fleet and/or permanently destroy the system you're in/going to every time you use this cool thing" is not a reward, it's an invitation to savescum like crazy until you're so tired of it you just ignore the feature entirely. Similarly for colony AI cores, there's very little that AI cores can do which does not boil down to "make me more money". If I had a choice between risking AI cores taking over my colonies or just AFKing for an ingame month to achieve the same end result - more money - why would I ever go with the former? Hell, if I had a choice between using AI cores to make me more money at the risk of them taking over my colonies, or selling said AI cores and making money with no attached risk, why would I ever use AI cores as anything but vendor trash?