This is a tricky thing to achieve because Revolution Slider adjusts the dimension of the slider depending on the size of the screen and the form's height also changes accordingly to accommodate its content to the container.
You can try using this code snippet here which sets the height of the columns equal in the initial load.
This feature is not currently supported in Cornerstone. It could be possible with custom development, but this would be outside the scope of support we can offer. You may wish to consult a developer to assist you with this. X is quite extensible with child themes, so there are plenty of possibilities.
As for the background image in a flip card, I checked the homepage of your site and the background images seem to fill the entire column they are set on.
Thanks for understanding. Take care!