Hi Micah,
When you say "Store Broker keeps pegging my CPU" can you provide us a screen shot of Window?
How to include a screenshot in your post
http://answers.microsoft.com/en-us/windows/wiki/windows_other-windows_programs/how-to-include-a-screenshot-in-your-post/2594b08e-32a3-476a-85a6-b021181be7e4
Store Broker (wshost.exe) is basically in charge of metro permissions. If you have a bunch of metro apps running it will get larger. You can’t kill the process because that would kill the metro apps.
You can perform these steps and check if that works.
Method 1:
Run the system maintenance troubleshooter.
Follow these steps:
a) Press the ‘Windows + W’ key on the keyboard.
b) Type troubleshooter in the search box and then press enter.
c) Click system and security and run the System maintenance troubleshooter.
Method 2:
Let's perform clean boot and check:
Clean boot helps in eliminating software conflicts.