I'd like to generalize a little here. Regarding events, I think the design rules/philosophy should be -
Events can offer opportunities if special conditions are met and/or costs are paid.
This would extend to things like the Graveyard. Rather than "do this thing or get bad permanant result", it should be "Do this and get something good, or something you couldn't otherwise get." Example, The graveyard would have some benefits as a tile improvement, but isn't normally buildable.
Events can offer permanant goodies, but only temporary bad effects.
Temporary could mean many things. Anything which has a specific targetted way to remove it. Fallout with ways to clean, monsters you can kill, a penalty you just have to wait out, etc.
These rules I think would help event be Interesting without being frustrating. They can be difficult to deal with, maybe even empire-killers if the exact wrong event happens in the wrong place at the wrong time! But there should be some way to galvanize your people to deal with the situation.