Level 5
Not if you have autosanbox on or hips on, both are stronger.
Well, you can very well say that whole Avast is not needed if you have HIPS and AutoSandbox and maybe you will be right, but if you have Avast then why don't you use all of the available security options. BB is not a dedicated antiexploit but what if in some very strange way it catches an otherwise safe by Comodo app like a browser being exploited?