"Fast With No Exceptions" Crash Reasons

Unity Engine
1

Hi there,
I am wondering if I set my game to run at “Fast With No Exceptions”, do public vars, which I have created in scripts that are never used, never filled, can they contribute to a crash? Just looking over my code and I have a few of these.

*few = dozens.

2

Bumping. Just wondering why, this setting is more prone to crashes. The reason I ask is because a program is a program is a program, and if it runs it runs. Why would upping the processing speed make a program more prone to crashes?

Thanks in advance.