Problem reinstalling PostgreSQL after installing Parallels

I’m trying to reinstall postgresql on my mac (yosemite) after installing parallels seemed to mess up permissions to directories that psql and homebrew need. I was able to force-uninstall psql, but when running brew doctor before reinstalling I get:

Warning: The /usr/local directory is not writable.
Even if this directory was writable when you installed Homebrew, other
software may change permissions on this directory. Some versions of the
"InstantOn" component of Airfoil are known to do this.

You should probably change the ownership and permissions of /usr/local
back to your user account.

The other Warnings I get apply to /usr/local subdirectories.

I see many similar threads that recommend changing ownership via:

sudo chown $(whoami) /usr/local/

...but my question is, if I use this to change ownership & permissions back to my user account will this mess up Parallels?

Sorry, new to this, don’t quite understand the relationship between parallels & /usr/local/