>>After I insert the layer in normal mode, it is free for me to move anywhere.

>>But when I click on preview mode and click back to normal mode, the layer can't move anymore. Why?

>>How I can solve this problem?

 

We will investigate this issue and get back to you as soon as possible.

>>Another question is how I can remove the blue color line of the layer? I don't want the user see the line in normal mode.

You can turn off the "visible borders".