I am attempting to place some GUI elements for my game on the screen. These GUI elements will later have text placed on top of them. Are OnScreenImages an acceptable way to put the images there? Also, is there any way that I can keep the original size of the image and not have it rescaled to make a square? I am loading an image that is 1024x64 and it is being rescaled to a square for some reason.

The image is not rescaled to a square at all, it’s just that the texture coordinates of the card that OnscreenImage generates are in the 0-1 range.
To avoid that, set a scale on the card.