Why would you not run the test with stock se4 and a few neutrals? Processing would take much less time then...
Setting event chances over 100 is pointless, as 100 makes one event occur every turn. You can not have more than one event occur in a turn. But, higher numbers do not cause any crashes or anything. I set it to 3000 or so in one of my tests a while back.
I would like to point out that SJ made an entire scenario from a savegame where the star in his home system went nova (and there was only one home world). It is called Exodus, and it can be found
*here*. It is for SE4 classic (pre-gold) and P&N 2.3c. I do not recall any changes being made to how events work in Gold, and see no mention of any changes in the History file related to this...