Understanding Hummingbird minification error message

Hello Everyone,

I'm learning how to use Hummingbird and it was going well until I installed a couple of plugins that make calls to google fonts and Hummingbird says they are all errors due to querystring parameters.

1) please help me understand why Hummingbird flags these
2) why the options to minify + combine are greyed out
3) why Hummingbird is stuck at "Pending"
4) What should I tell the plugin developers about the performance of their plugins? Can I do something to fix these errors?

When I click one of the offending font entries, the browser opens a window full of CSS. What is that?

Thank you for your support.