Thanks for the reply.
On the images not filling the slider space:
I feel silly; the issue was I still had the other Genesis (non-responsive) Slider installed. It names it’s custom thumbnail ‘slider’, the same as this plugin. Once I deleted that, there were no issues.
On the responsive text:
I got it working, but it pulls its style from the my post title, which doesn’t always fit in the slider. I’ll play with the plugin and see if I can give it its own style.