The custom model background image is not for show on Layout its only used to place it behind the cells so you can take a picture of your element and then create a grid over the picture and click the cells where you see the lights on the picture to create the nodes. You use the slider to dial down the transparency of the background image. Make the grid bigger when curves or angles need better detail. Use the auto-number feature to be able to just click, click, click to enter the numbers.
If you created a model as a single pixel then yes the grab point is really small. Drag select it then use arrow keys to move it.
Not sure about the freeze. Maybe make sure you create some E1.31 outputs on the Setup page so that we have a channel definition. I've never seen this kind of problem so it would be nice to figure out what users are doing to cause it because you're not the first to have that happen.