Soundflower difficulties
I was having audio issues with soundflower causing digital noise once I got it working.  This work around may help your issue too.

A friend suggested an idea that he had been shown. Setup soundflower as a midi simultaneously with your regular output. Therefore instead of routing through soundflower for your output (which seems to cause the issue), it routes each as their own output. So far seems to be working on my recording meters without the overdrive static. Here is the how to on this.

Also, if you are looking for more control I found software from Prosoft that allows for audio adjustment using hear or individual app volume control through hear or soundbunny.