Definitly, YES. And a lot of great suggestions here.
I totally agree that these mega-events should be optional.
I'd like to go one step further: Instead an on/off-checkbox, give us some more options, like we have the galaxy setup:
MEGA-EVENT PROBABILITY:
- a slider on how often mega events happen. Never, extremly seldom, about once per game, several times per game...
MEGA-EVENT IMPACT:
- how severe the consequences are. Light (small invasion fleets turn up, little stuff explodes), medium (invasion fleets equal in strength to the players power show up, single systems explode), heavy (invasion fleets are more powerful than all existing civs together, whole sectors blow up etc)
Shouldn't be to hard to implement and would be a great way to give everybody the gaming experience he likes.