Two questions...

[Vonwert]

1.) Is it possible to do parallel events? Have one event going on at the same time another event is happening?

2.) Is it possible to have both fog and snowing options going on?

[thelegendaryX]

In that first question, what exactly did you mean? Obviously, you can't have overlapping message displays or two storytellers running at once. But I wonder what your need for it could be?

I'd like an answer to that second question myself. But I'm thinking it's a negative.

[Lausen]

1.) Is it possible to do parallel events? Have one event going on at the same time another event is happening?

2.) Is it possible to have both fog and snowing options going on?

It's a no for both.

[Seraph]

1.) Is it possible to do parallel events? Have one event going on at the same time another event is happening?

Not quite clear on what you're asking, but it is possible to have multiple auto-events process at the same time, depending on the event contents.
You can add/remove items, add/subtract/modify variables and modes etc.
Most stuff, I assume, cant be done though.