Make a duplicate event id then test it by launching it via the console and via a separate event and see what happens. That way you can tell if it works like decisions in that either way it breaks or if it still works but like with the traits if launched then only the last one fires or if both happen at the same time.For #2, I know the last time I tried it (a few patches back) the validator had a fit and so did the error logs, but I haven't yet taken the time to figure out the actual behavior.
I imagine that they just will not work